A modern advanced analytic approach to cost and performance loss analysis of ulnar collateral ligament surgery to Major League Baseball teams

Abstract

Background

Ulnar collateral ligament (UCL) surgery has become increasingly prevalent among Major League Baseball (MLB) pitchers. While its clinical implications have been extensively studied, the economic and performance impact on MLB teams remains incompletely understood.

Methods

Cost analysis on all MLB pitchers who underwent UCL reconstruction between 2014 and 2024 was conducted. Pitchers were identified, and data were collected using public databases affiliated with MLB and used in previous studies. Economic losses were calculated using 2 primary components: (1) salary cost of recovery (COR), which quantified salaries paid to injured players during recovery, and (2) performance cost, a metric we defined using common FanGraphs wins above replacement (fWAR) conversions to estimate lost player contributions.

Results

During the study period, a total of 276 UCL surgeries were performed from 2014 to 2024. Over the past 5 seasons (2020-2024), the number of UCL reconstructions in MLB pitchers has significantly increased to an average of 29.0 ± 4.7 surgeries per year compared to 21.8 ± 4.3 surgeries per year the 6 seasons prior (2014-2019; P = .05), with a peak of 35 surgeries in 2023. From 2014 to 2024, the COR salary losses adjusted for inflation totaled over $1.26 billion, with an increase in average COR over the past 5 seasons ($141 million ± 72 million) compared to the 6 seasons prior ($92 million ± 52 million; P = .14). The estimated COR per player for starters, relievers, and closers was $7.3 million, $2.3 million, and $11.5 million, respectively. The average cumulative fWAR lost per pitcher was 1.9, translating to an estimated annual market loss of $14.3 million per player. The total cumulative fWAR loss across all players was 452.8. Using the conversion of 1 fWAR is equal to approximately $7.5 million in salary, an estimated $3.4 billion worth of performance value was lost for the entire study period.

Conclusion

UCL injuries that require surgery impose an increasingly significant financial burden on MLB teams, leading to the loss of $1.26 billion dollars in salary paid out to injured players and likely over $3 billion worth of performance value lost to injury to teams over 10 years. Players also struggle to provide the same value in fWAR as they did prior to injury. This study shows that investing in UCL prevention and recovery efforts can potentially save teams, players, and local communities millions of dollars.

Ulnar collateral ligament (UCL) injuries in Major League Baseball (MLB) pitchers have surged in recent years, resulting in a corresponding increase in ulnar collateral ligament reconstructions (UCLRs, otherwise known as Tommy John Surgery).^2,6,13 While prior research has extensively examined return-to-play rates,^9,11,16,18 postsurgical performance outcomes,^1,2,16 and risk factors associated with these injuries,^1,15,17,22 there remains a paucity of literature addressing the financial and loss-of-performance burden on MLB teams. Most recently, Meldau et al¹⁹ published a cost analysis of UCLRs in MLB from 2004 to 2014, with teams losing an inflation-adjusted $395 million in salary to pitchers recovering from Tommy John Surgery.

Since then, the escalating salaries of professional pitchers and the growing reliance on performance metrics in the modern advanced analytic area has teams and owners hyper-focused on maximizing value and cost-efficient roster construction. In baseball, contracts are fully guaranteed and prohibitive luxury tax penalties instituted on teams in the most recent collective bargaining agreement signed in 2023 has curbed exorbitant spending. This makes losing a star pitcher, who can make as much as $40 million per season, devastating to a team's chance to compete. Not only is his salary now “wasted,” but teams then need to find a way to replace the value he produces on the roster if they want to remain at the same competitive level. This may result in additional money spent on free agents or in trades to obtain a quality major league–level replacement for the injured player, which often requires giving up cost-controlled prospects on minimum salaries who can provide significant surplus value in the future and thus more efficient roster construction.

To determine a player's hypothetical value on the open market, teams commonly convert a player's FanGraphs Wins Above Replacement (fWAR), which is a quantitative and qualitative measure of how many wins a player is worth to his team compared to a replacement level player, into a monetary value to help drive contract negotiations with the player and their representatives. Although there is slight variation to the exact conversion depending on overall team spending throughout the league in that particular season, conservatively, one fWAR has been deemed to be worth at least $7.5 million in salary since the 2014 season.⁷ As fWAR increases to over 2, this conversion likely underestimates a player's true value on the open market, as a player of this quality is increasingly rare and provides substantial value to the team while only taking up a single roster spot.^7,19,20 While metrics such as fWAR are frequently relied on to evaluate player value and drive contract negotiations and personnel decisions, it has not yet been used to evaluate the financial implications for teams of UCL injuries requiring surgery in MLB pitchers.

Therefore, the primary objective of this study is to provide a more comprehensive cost and loss-of-performance analysis to teams, using both direct loss of salary and lost player performance value using fWAR to characterize the burden of UCL surgery in pitchers to MLB teams. Understanding the degree of financial loss is imperative to convince teams and other associations to make the financial decision to invest in future UCL prevention efforts. Our secondary objective was to evaluate trends in UCL injuries and their associated financial and performance impact both during recovery and after successful return to play, along with identifying which pitchers have the greatest financial impact on MLB teams when injured.

Materials and methods

Study design

Data collection was conducted using entirely public databases that have been used in previous studies,15, 16, 17 therefore, a formal institutional review board review was not required. A retrospective analysis was conducted on all MLB pitchers who underwent UCL surgery from January 1, 2014, to December 31, 2024. UCL surgeries were identified using a public database that has been cited repeatedly throughout the literature²⁴ and were then cross-referenced with another public database and official press releases.²¹ Additional publicly available databases, including Baseball Savant,⁴ FanGraphs,¹⁰ Baseball Reference,³ and Spotrac,²⁵ were then reviewed to obtain demographic, return-to-play, fWAR (FanGraphs), and salary data for each player identified in the study period. Inclusion criteria for fWAR analysis were pitchers who underwent UCLR and who played in the MLB in the season immediately prior to surgery, resulting in 34 cases being excluded from this analysis for not having an available fWAR metric for the season preceding injury. Both primary and revision UCLR surgeries were included in this analysis.

Data collection

Demographic data, including age, handedness, position (starting versus relief vs. closing pitcher), and league played in (American vs. National League), were recorded and stored in a Microsoft Excel sheet. For this analysis, closing pitchers were defined as those with finished games representing ≥40% of their total appearances. Time missed for each pitcher was defined as the number of MLB regular season days absent from the date of UCLR surgery to the player's return to competition (defined as appearing in at least one MLB level game). Players who required multiple seasons to return were evaluated based on regular season days missed for any season following the injury and prior to their return.

Economic and performance loss was calculated based on 2 primary components: Salary cost of recovery (COR) and performance cost (PC) using fWAR, respectively. In order to estimate the economic impact of UCL injury and subsequent surgery secondary to salary loss, each player's annual contracted salary was divided by the number of regular season days (181) to determine a daily rate. This approach has been similarly used in prior investigation, which served as a foundation for this paper, to estimate cost of UCL injury in historical cohorts.¹⁹ If player contract data were unavailable (n = 6), the MLB minimum salary for the year of injury was utilized. These players were ultimately not excluded because it is mandatory for teams to pay these individual players the league minimum salary, and the minimum salary was chosen for these players to avoid overstating the financial loss. The total salary paid during the player's absence (time of surgery to return to MLB-level play) was then calculated by multiplying the daily salary rate by the number of regular season days missed, as players are paid according to regular season time. For players that did not return to MLB level, their salary at the time of surgery and the average number of regular season days missed for the entire cohort was utilized as a proxy for COR calculation. This is because it is difficult to determine with public data if a player did not return because they retired or only made it to the minor leagues, vs. if they had guaranteed contracts. These financial metrics were adjusted for inflation by using government Consumer Price Index data,^2,28 with all “inflation-adjusted” values set to the 2024 US dollar value for accurate reporting purposes. Yearly trends in COR were also recorded.

fWAR is a cumulative statistic that measures a player's quantitative and qualitative performance value in all facets of the game by comparing how many more wins he is worth than a replacement-level player and is widely used throughout the league to evaluate player performance. A replacement-level player is defined as a readily available minor league or bench player who can be expected to perform at a minimal level for the position. fWAR is calculated on a per-season basis and is expressed as a positive or negative number of wins, with 0 representing replacement-level performance, positive values indicating above-replacement contributions, and although rare, negative values signifying below-replacement performance. The expected fWAR contribution of players after surgery in this analysis was estimated based on preinjury performance (ie, the full season immediately preceding UCLR surgery). A full season prior to injury was defined as playing in more than half of the season's games.

Lost fWAR was determined as a combination of 2 factors: (1) fWAR lost during recovery and (2) fWAR secondary to performance decrease following return. For players that did not return to MLB-level play, an fWAR of 0 was given for a single season following injury. The lost fWAR value was converted to financial terms using the estimated market rate of 1 fWAR being worth about $7.5 million in salary, the reported number at the beginning of this study period during the 2014 season. Yearly trends in fWAR lost were also recorded and used for prediction of value loss due to decreased performance in subsequent seasons. To avoid overestimation, no further fWAR value loss in the subsequent 3 years was attributed to the UCLR for these players, and any negative fWAR values were technically considered as beneficial in regards to team performance.

Statistical analysis

Exploratory data analysis was performed to describe the sample distribution. The study team discovered that all variables did not satisfy the normality assumption demonstrated by the Shapiro–Wilk test (P < .001). As such, the Kruskal–Wallis comparison test and Wilcoxon rank-sum test were used to analyze the data nonparametrically. Kruskal–Wallis comparison test and Wilcoxon rank-sum test were utilized to detect differences among cohorts (ie, pitcher classification, index years, primary vs. revision reconstruction, etc.) within the study. Post hoc analysis was performed using Bonferroni test of correction. All statistical analyses were performed using Microsoft Excel Version 16.35 (Microsoft Corp. Redmon, WA, USA), SPSS Statistics Version 25 (IBM Corp., Armonk, NY, USA), and R Studio Version 2023.06.2 (Posit, Boston, MA, USA). Statistical significance was defined by an alpha level of < .05.

Results

Between January 1, 2014, and December 31, 2024, 276 UCLR surgeries were performed on 271 unique pitchers; 44 (15.9%) of these were revision surgeries. Players who underwent multiple surgeries were included once for demographic analysis but treated independently in subsequent analyses, with each surgery representing a new instance of salary and performance value lost. Notably, many of the pitchers who underwent revision during the study time period had their primary surgery done either before the time period or while playing at a lower level (high school, college, A+, etc.). These primary surgeries were not included in the analysis. Of these 276 total procedures, 242 cases had a baseline fWAR from the preceding season and thus were included in the cost analysis, while the remainder (n = 34) were excluded.

The mean age at the time of reconstruction was 27.5 ± 3.2 years (range: 21-40). Half of the pitchers (135) were on American League teams at the time of injury. There were 125 starters, 133 relievers, and 13 closers that underwent reconstruction, with a predominance of right-handed pitchers (73.4%) (Table I).

Table I.

Demographics.

Variable	Cases n = 271
Age (yr)∗	27.5 ± 3.2 (21-40)
Position†
Starter	125 (46.1)
Reliever	133 (49.1)
Closer	13 (4.8)
Throwing hand†
Right	199 (73.4)
Left	72 (26.6)
League†
American	135 (49.8)
National	136 (50.2)

SD, standard deviation.

Demographic information.

^∗Values are expressed as mean ± SD (min–max).

^†Values are expressed as number (percentage).

Over the past 5 seasons (2020-2024), the number of UCLRs in MLB pitchers increased to an average of 29.0 ± 4.7 surgeries per year compared to 21.8 ± 4.3 surgeries per year during the 6 seasons prior (2014-2019; P = .05), with a peak of 35 surgeries in 2023 (Table II). This was primarily due to an increase in the number of starters receiving UCLR, with an average 14.2 ± 6.1 starters undergoing surgery in 2020-2024 compared to 9.5 ± 2.4 in 2014-2019 (P = .14), peaking in 2023. When stratified by primary vs. revision surgery, primary surgeries tended to increase over the study time frame, while the rate of revision surgery was relatively stable (Fig. 1).

Table II.

UCLR by position and year.

Type of pitcher	2014	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024	Total
Starter	11	10	11	6	12	7	13	7	11	23	17	128
Reliever	16	13	9	10	11	8	17	17	14	10	10	135
Closer	0	3	1	1	0	2	3	1	0	2	0	13
Total	27	26	21	17	23	17	33	25	25	35	27	276

UCLR, Ulnar collateral ligament reconstruction.

Figure 1.

Number of UCLR surgeries performed by index year stratified by surgery type. UCLR, Ulnar collateral ligament reconstruction.

The average annual salary for the cost analysis cohort (n = 242) at time of reconstruction (adjusted for inflation) was $3.9 ± 7.5 million (median: $755,109, range: $661,938-$72.2 million). Six pitchers had no salary information available, and the MLB salary minimum for the preinjury year was used as a conservative estimate to not overestimate the financial impact of their UCL surgeries. This equates to an average daily salary of $21,321 ± 41,488 (median: $4,172). Average annual salaries were significantly different for the 3 distinct pitcher classifications, with starters, relievers, and closers making $5.7 ± 10.0 million, $1.5 ± 2.1 million, and $8.3 ± 5.7 million, respectively (P < .001). The distribution of salaries for the overall cohort and then subgrouped based on pitcher type are shown in Fig. 2 a and b.

Figure 2.

(a) Violin plot of the average annual salary (adjusted for inflation) for pitchers undergoing UCLR, showing significant skew. The violin plot shows the density of players falling within the y-axis salary ranges for our study cohort. (b) Overlaid violin plot of average annual salary lost (adjusted for inflation) by pitcher type, using a logarithmic (base-10) scale in millions of dollars. The violin plot shows the density of players falling within the y-axis salary ranges for each pitcher type. To accommodate the wide range and skewness of salaries ($0.66 M-$72.2 M), the logarithmic scale compresses high salaries (eg, $72.2 M) and spreads lower salaries, facilitating easier visualization. UCLR, Ulnar collateral ligament reconstruction.

The overall average number of total days lost prior to return to MLB-level play was 608.2 ± 260.8 days, with 288.5 ± 121.0 days (47.4%) of those being “in-season.” The total salary loss (COR) from 2014-2024 was estimated at $1.26 billion (adjusted for inflation). The year 2023 had the highest COR of $245.3 million (Table III). The highest COR secondary to a single player was $61.2 million, who was a starter. The estimated COR per player was significantly different between starters, relievers, and closers at $7.3 million, $2.3 million, and $11.5 million, respectively (P < .05) (Fig. 3).

Table III.

Yearly salary loss secondary to cost of return by position and year.

	2014	2015	2016	2017	2018	2019	2020	2021	2022	2023	2024	Total
Position
Starter	65.5	113.6	26.1	50.3	62.5	28.7	112.6	36.5	51.6	200.4	101.8	849.4
Reliever	38.3	44.2	10.5	21.9	11.3	10.8	24.3	21.3	33.2	14.0	40.3	270.2
Closer	0.0	31.3	2.0	8.6	0.0	26.6	32.6	6.1	0.0	30.9	0.0	138.1
Total	103.7	189.0	38.6	80.8	73.8	66.1	169.5	63.9	84.8	245.3	142.1	1,257.7

Values are reported as millions of US dollars, adjusted for inflation

Figure 3.

Distribution of salary loss secondary to cost of recovery following UCL surgery in Major League Baseball pitchers. UCL, Ulnar collateral ligament.

The average fWAR prior to the year of surgery was 0.96 ± 1.2 (range: −1.0 to 6.4), equating to an estimated performance loss market value of $7.2 million per player per year. fWAR was significantly different among the pitcher types (P < .001) (Fig. 4). Starters had the highest initial individual fWAR per player of 1.5 ± 1.4, followed by closers (1.2 ± 1.0) and relievers (0.4 ± 0.6).

Figure 4.

Violin plot of preinjury fWAR stratified by pitcher type. fWAR, FanGraphs Wins Above Replacement.

For the season immediately following the index, the fWAR of players returning to play (n = 75) dropped to a mean of 0.38 ± 1.16. Notably, these players with quick returns had a higher original preindex fWAR (mean: 1.3 ± 1.1) compared to the population at large. This gives an overall decrease of −0.9 (95% confidence interval {−0.7, −1.2}, P < .001) from preinjury to the first season after returning from surgery. One hundred thirty patients had a documented fWAR in their second season after returning from surgery, with a mean of 0.72 ± 1.20. Ninety-eight patients had a documented fWAR in their third season after returning from surgery, with a mean fWAR of 0.73 ± 1.17 (Fig. 5). For pitchers that had a documented fWAR at any point in the 4 seasons following surgery (n = 160), only 71 (44.4%) returned to a level at or above 90% of preinjury fWAR. For players that had a documented fWAR for at least 2 of the 3 seasons following return from surgery (n = 105), the mean fWAR across seasons played was 0.71 ± 0.92. Of these 105 players, only 33 (31.4%) averaged an fWAR that exceeded 90% of their preinjury score.

Figure 5.

Average fWAR for the entire study cohort at various periods relative to surgery. Each year post-surgery represents the first, second, and third season after returning from surgery. fWAR, FanGraphs Wins Above Replacement; UCL, Ulnar collateral ligament.

The average cumulative fWAR loss per player (including for the index season and over the 3 seasons following return from surgery) was −1.9. ± 3.6 (range: −19.4-8.6). The total cumulative fWAR loss across all players was −452.8 (Fig. 6). The year of index injury with the highest consequence was 2020, with a cumulative fWAR loss in players injured in 2020 of −98.5 following the index surgery. Using the estimated fWAR ∼ $7.5 million conversion, this equates to a total loss of $3.4 billion worth of performance value for the entire study period and $738 million for 2020 alone. The year 2020 was characterized by a number of high performing pitchers succumbing to injuries, leading to a large loss of fWAR, while 2021 was characterized by a number of lower-performing pitchers getting injured, and thus a corresponding small loss in fWAR.

Figure 6.

Yearly trend of mean fWAR lost per season. fWAR, FanGraphs Wins Above Replacement; UCL, Ulnar collateral ligament.

Subgroup analysis analyzing primary vs. revision UCL surgeries was also conducted. The estimated COR per primary UCL surgery was approximately $5 million, while the estimated COR for revision UCLR was $6.4 million. The average cumulative fWAR lost per primary surgery was 1.8, translating to an estimated annual market loss of $13.5 million per player, while the average cumulative fWAR lost per revision UCLR was 2.2 translated to an estimated annual market loss of $16.6 million per player. Although revision UCLR trended toward being more costly in both COR and performance value lost, there were no significant differences between primary and revision UCL surgery (P > .39).

Discussion

The findings of this study demonstrate the profound economic and performance burden imposed by UCL injuries requiring surgery on MLB teams through the direct costs of player salaries and the indirect loss in player value and production as quantified through fWAR. Our novel methodological framework, which integrates fWAR with salary-based metrics to provide insight into the indirect costs of UCL surgery on MLB teams, offers a new approach to understanding the true financial and performance toll of UCL surgeries, revealing a loss of $1.26 billion in salary and a cumulative PC of $3.4 billion between 2014 and 2024. The performance impact of UCL injuries continues even after the player returns from injury, as players struggle to provide the same level of value. Revision UCL surgery tended to be more costly than primary UCL surgery, although these differences were not statistically significant. Overall, these findings provide a more holistic view of the economic and performance impact of UCL surgery and shows that investing in UCL prevention and recovery efforts can potentially save teams, players, and local communities millions of dollars.

Meldau et al's¹⁹ cost analysis studied the time period between 2004 to 2014 in MLB pitchers. During this timeframe, they described a nearly 3-times increase in the amount of primary UCLRs at the end of their study period (2014) compared to the beginning (2004), a trend consistent with our study in the 10-year period after their analysis. By 2024, the number of UCL surgeries surged to an average of 29.0 ± 4.7 surgeries per year, compared to 21.8 ± 4.3 surgeries per year in the 6 seasons prior (2014-2019), with a peak of 35 surgeries in 2023. The total number of UCL surgeries from 2014 to 2024 in our cohort represents a 25% increase compared to the total amount in 2004 to 2014, further highlighting the alarming rise of UCL surgeries during modern baseball times. Even further, while the trend increase between starting vs. relief pitchers is relatively equal over the 2 different study periods, recently in the past five years this trend seems to be primarily driven by an increase in starting pitcher injuries, particularly since 2023. In this modern advanced analytic and pitch-tracking era, Mastroianni et al¹⁸ identified that pitchers who threw harder with less fastball usage, had superior overall pitching ability (Pitching+), and strike-zone command (Location+) were more associated with injury, indicating that the constantly improving ability of pitchers in today's game is contributing to the injury epidemic.

In regards to cost, Meldau et al¹⁹ found a COR of $395 million following Tommy John surgery. In contrast, our study shows a markedly higher degree of financial burden secondary to the COR from UCL surgery, which makes sense as the number of injuries has increased and the wealth of MLB contracts has risen markedly over the past decade.^10,25,26 Similar to our study, starting pitchers accounted for the greatest total COR, while closers had the highest per-player, and Meldau et al¹⁹ also demonstrated a significant baseline salary increase from the decade prior to the period they studied.

However, Meldau et al¹⁹ did not include a PC analysis, which we believe is critical to give insight into the indirect costs of UCL surgery through loss of performance value to MLB teams. Using fWAR is a unique approach to assess the financial impact of UCL injuries in the league and is commonly used by teams as a way to judge a player's value and performance. In the 11-year period of our study, we found a cumulative total of 452.8 fWAR lost secondary to UCL surgery, worth an estimated $3.4 billion. This also likely underestimates the true loss of fWAR to teams, with our use of one fWAR being worth $7.5 million in salary (as it was at the beginning of the examined study period) is likely an underestimate with more recent projections for 2018-2022 estimating $8.8 million per one fWAR,²⁵ while average team payrolls and player salaries has only increased since then.^5,7,12,26 Thirty-four cases were also excluded from this analysis for not having an available fWAR metric for the season preceding injury, but most likely would have provided significant additional value to teams.

Our analysis reveals a statistically significant decline in mean fWAR by an average compared to preoperative levels of 58% at 1 season after returning from surgery, 29% at 2 seasons, and 23% at 3 seasons after returning from surgery. This is a similar trend to another study by Mastroianni et al¹⁶ investigating return to performance following UCL surgery from 2018 to 2023, which identified a presurgery fWAR of 1.57 and postsurgical decrease to 0.35 in their first qualifying season following return to play.¹⁶ This study found a small decline in performance, which may have occurred independent of UCLR, with the average age of players being 27.6 years old and 29 years old in this current study, both ages generally considered to be in a player's “prime” of their career. However, Mastroianni et al attributed a majority of that decline to decreased workload after return to play, as teams generally are very conservative with pitch and inning counts while there was a more mild decrease in performance level.

This is likely why starting pitchers and more inexperienced pitchers were less likely to return to performance in their study, given they would be put on more strict innings limits compared to relievers and to not compromise their future health. Older pitchers also were less likely to return to performance, perhaps because they were closer to retirement and the injury may have accelerated their timeline. Pitchers who threw faster were less likely to return to performance, while pitchers who had more spin were more likely to return to performance, suggesting that surgery may impact “power” pitchers over more “finesse” pitchers. In total, this suggests that surgeons do well in getting pitchers back to near their previous ability level, but pitchers struggle to get back to pitching as much as they used too. To our knowledge, no study has investigated whether a conservative approach to bring pitchers along slowly is safer than pitchers more quickly returning to preinjury workload levels after returning to play, and whether a faster return would impair their pitching ability.

The subsequent moves needed by teams to be made in order to compensate for the loss of performance value, or risk having an unsuccessful season, can be very costly and often needs to be accounted for over 2 seasons. Furthermore, another study by Mastroianni et al¹⁵ found that increased fWAR and pitching ability were significant risk factors for UCL surgery, suggesting that typically a team's more valuable pitchers are getting surgery. While the total fWAR lost by teams can be recouped primarily by promoting minor league prospects, signing a free agent, or making a trade, each of these transactions contains a direct and indirect cost. Although this option bears the least direct cost for the team initially (rookies are on a minimum salary), calling up a minor leaguer begins their service time clock, potentially fast forwarding the time until they are able to reach free agency and negotiate a bigger contract. This is during an era when MLB teams are increasingly conscious of delaying star prospects from free agency to save substantial money on the backend of their rookie contracts.²³ Pitchers also generally perform better after their first couple of full seasons, and thus just promoting minor leaguers would not likely lead to equal value back,^8,10 especially if there was no capable prospect available.

Signing another free agent has additional direct costs, with a player having a higher-than-minimum salary (sometimes substantially) and/or often lower performance, especially if the injury occurs during the season when more talented free agents are rarely available. Trading for a replacement can be even more costly, usually acquiring additional direct salary costs along with giving up cost-controlled prospects who could eventually provide substantial surplus value to an MLB team. Future studies that determine the true cost of all of these subsequent moves can better characterize the true financial value of these transactions, but will require extensive analysis of every roster decision made in result of a UCL surgery over a study period, which can be difficult to ascertain without inside knowledge into team strategy. When considering the likely underestimation of our fWAR conversion used, along with the total fWAR lost secondary to the 34 surgeries being excluded from this analysis, it likely means our $3.4 billion performance lost finding is underrated, although the exact financial impact to teams from loss of performance value is difficult to clearly ascertain.

On the other hand, not replacing a productive player can lead to poor seasonal results, which significantly impacts team-specific revenue through decreased stadium attendance, merchandising, and franchise value, especially if a star player is injured. Playoff appearances make up a significant source of team and player income; the player's pool of 2023 World Series champions reportedly reached $107.8 million, with the players getting 60% of the total gate receipts for all guaranteed playoff games, and the owners getting 100% of ticket receipts for all games that are played beyond the guaranteed number. The commissioner's office gets a 15% share of all gate receipts.¹⁴ Future player contracts are also generally decreased after a UCL surgery as the average fWAR struggles to recover. Overall, both teams and players have substantial financial incentive to address the rise of UCL injuries in baseball.

Limitations

This manuscript is not without limitations. Firstly, the analysis relies heavily on fWAR as a primary metric for assessing player value. While fWAR is a widely accepted measure in baseball analytics and all of MLB, teams have their own proprietary data to determine player value that is not available publicly. Thus, the conversion of fWAR to contract value is also subject to bias, although FanGraphs has been used in multiple previous studies and is generally well regarded throughout the league.15, 16, 17^,27 The conversion also varies slightly each year based on the money spent by teams in a particular season, although we used a more conservative estimate to avoid overestimation. The generalizability of this study may change in future years as salaries grow and with future collective bargaining agreements, albeit salaries have generally ranged from $150 to 170 million since 2019, and any future salary cap will likely be counter-balanced with a salary floor.^10,25 For players that did not return to MLB level, their COR was estimated based on the average number of regular season days missed for the entire cohort, which is subject to bias but was what we felt to be the best way to capture their impact given the limitations in the public data previously described. Another major limitation is our reliance on public data; however, the same sources are either affiliated with MLB or have been used extensively in previous studies.15, 16, 17 The fWAR conversion metric also does not take into account the increased value of elite pitchers, efficient roster construction, and the amount of fWAR lost due to loss and decline of performance. The potential economic impact of UCL injuries treated nonoperatively, or surgeries in minor leaguers, is also not accounted for in this study but are by MLB team's payrolls, which further increases the financial burden of UCL injuries to professional baseball.

Conclusion

UCL injuries that require surgery impose an increasingly significant financial burden on MLB teams, leading to the loss of $1.26 billion in salary paid out to injured players and over $3 billion worth of performance value lost to injury to teams over from 2014 to 2024. After returning, players also struggle to provide the same value in fWAR as they did prior to injury. This study shows that investing in UCL prevention and recovery efforts can potentially save teams, players, and local communities millions of dollars.

Disclaimers:

Funding: No funding was disclosed by the authors.

Conflicts of interest: Christopher Ahmad has received: royalties from Arthrex; consulting fees from Arthrex; nonconsulting fees from Arthrex. The other authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.