Following another effective season, Joe Musgrove underwent Tommy John surgery in October of 2024 to repair a torn UCL.  Ready to return in 2026, what does history tell us about Musgrove’s chances to rebound after his major setback?

Entering the 2025 MLB offseason, the Padres’ found themselves in major need of help at starting pitcher. Their 2o24 unit finished 16th in the MLB in ERA, and was preparing to lose their top two pieces in free agency.

While San Diego has been in active pursuit of starting pitching in free agency, a internal option is available. Joe Musgrove will be a full go in 2026, as he hopes to help fill a hole in the rotation.

It’s a welcomed sight to see Joe Musgrove with health concerns out of the question. However, his effectiveness upon returning, is very much in question. Historically, returns from Tommy John have been both masterful and ugly. However, the list is long and relies on several factors such as arm slot, velocity, pitch selection and more.

In order to formulate a more specific prediction, I’ve identified pitchers similar to Musgrove who also underwent Tommy John surgery. So, here’s what the past can tell us about what we may see out of Musgrove in 2026 and beyond.

The reference players

For the comparison, Kenta Maeda, Jameson Taillon, and Lance McCullers Jr. are the best reference options. This trio of hurlers shares all of the following similarities with Musgrove:

• Right-handed starting pitcher (at the time of the injury and return)
• Low-90s fastball
• Around 20% primary fastball usage (Taillon is slightly higher)
• 6+ pitch arsenal

Additionally, each arm shares a specific similarity with Musgrove that can be tracked in a side pot of data.

Kenta Maeda shares nearly the same arm angle as Joe Musgrove, as well as similar mechanics. Jameson Taillon most accurately matches Musgrove’s pitch arsenal and selection, with a cutter-sweeper-curveball trio. Lastly, McCullers Jr. is the best comparison in terms of vertical drop— a key factor affected by TJ surgery.

With our reference data in place, let’s dig in to some numbers.

Velocity, spin rates, and pitch movement

Most general research on the effect of Tommy John on velocity indicates very little change. However, this baseline conclusion can be very misleading. Instead, the effect on velocity relies on how hard the pitcher threw before the surgery, and the effort level of the delivery.

For example, hard throwers such as Noah Syndergaard and Tyler Glasnow incrementally lost velocity by the year. The older Syndergaard, fell from 97.8 MPH to 92.2 over three seasons post-surgery. The younger Glasnow has only regressed 1.7 MPH in three seasons post-surgery.

However, the results look very different for pitchers who throw in the low 90s. Velocity generally did not change, and spin rate actually minimally increased following TJ. Results also indicate that induced vertical break favorably improved for most pitchers, with the determined by their fastball of choice. Sinkers generally gained sink, and four seamers generally gained rise.

For breaking balls, the most consistent development was an increase in spin rate and vertical drop. However, although the numbers increased, the actual shapes visibly lost natural bite and late break. Most specifically, curveballs and gyro sliders with depth were ‘loopier’, effectively reducing tunneling ability.

Joe Musgrove could be impacted by a loss of late action, but his repertoire is a bit safer than the reference players. Musgrove’s curveball is already more of a rainbow than a hammer, due to his high release point at the height of 6 ‘5. His sweeper is similar, and shouldn’t be affected the way a gyro slider would be affected.

Joe Musgrove since being activated off the IL on August 12th:

38 IP
2.37 ERA
0.89 WHIP
42 Kpic.twitter.com/eckm523lct

— Kirk Snyder (@dynastyinfo411) September 15, 2024

Baseline results, arsenal stats, and underlying trends

Between the reference players, general results were volatile.

Maeda minimally improved in both ERA and WHIP across a nearly identical amount of innings in his returning year. However, his numbers quickly took a turn down the road, eventually forcing Maeda into the bullpen in 2025.

Taillon’s first season back healthy was a regression, but still manageable at a 4.30 ERA. He’s aged the opposite direction, putting up successful seasons in both 2024 and 2025 for the Chicago Cubs.

McCullers was the outlier, as his procedure and setbacks took away two full seasons. He made 16 appearances in 2025 and struggled to the extent of a 6.51 ERA.

As touched on earlier, the biggest development was a change in shape of the breaking balls. While the change didn’t show up in the movement planes, it showed up in the results. All three pitchers saw notable declines in the whiff rate of their breaking pitches. Maeda saw a 5.9% decrease, and McCullers Jr. witnessed a massive 7.1% decline— an alarming drop for how frequently he uses his breaking balls.

Hand-in-hand with whiff rate, all three pitchers also regressed in chase rate. It’s clear that the change in shape of the breaking balls is the culprit of these trends, and it’s reflected in the development of usage rates as well. All three pitchers reduced their usage of breaking balls following Tommy John surgery.

There’s little margin for prediction here when it comes to Musgrove, but some form of consistency should be the expectation. He may lose some swing-and-miss, but once again, Musgrove is somewhat more protected. He’s not reliant on whiffs for outs, and he instead excels in limiting hard contact. Barring any unexpected development, Musgrove should sail back into the mid-three-ERA range.

Command and durability

One nugget that clearly popped out in the post-Tommy John sample size was an increase in home runs for all pitchers. This was primarily a byproduct of rust, most commonly in the form of hanging breaking balls. All three pitchers notably saw increases in Statcast’s “Meatball” rate, which indicates a pitch left in the middle of the plate. Taillon’s increase was the most extreme, going from 5.7% in 2019 to 9.1% in 2024.

Fortunately, durability hasn’t been an issue for soft-tossing starters coming off of Tommy John. While Kenta Maeda transitioned to the bullpen, his move was based more on effectiveness and roster strategy rather than arm durability. Taillon made 51 starts between 2024 and 2025, and hasn’t run into any issues. McCullers Jr. is an outlier, as he eased into his return in 2025 and only time will tell if he can return to prime form.

Musgrove is 33 years old, and has faced several other small scale arm-related injuries in his career to this point. His ability to stay in a rhythm of making strings of 10+ starts in a row during the season is probably the most important aspect of his return. Reaching 120+ innings in 2026 would be a reasonable but meaningful goal for Musgrove to reach in 2026.

Joe Musgrove gave up just one run on a national stage with a torn UCL. Absolute dawg. Will always respect him for giving his all for this city pic.twitter.com/akzpVFCEPw

— Talking Friars (@TalkingFriars) October 5, 2024

Conclusion

Overall, the verdict on Musgrove is pretty simple. Mechanically, he shouldn’t be impacted much by the surgery and should maintain a similar repertoire and movement profile. However, the concerns are mainly durability and command issues that could potentially negate his results.

With the re-signing of Michael King and addition of Triston McKenzie, the Padres aren’t as reliant on Musgrove for frontline starter production as they were the week before. However, it’s inevitable that Musgrove will be a core piece of the pitching staff. His efficiency and durability, could be the factors that tip the scale of the Padres’ rotation, from solid to strong.

Willy Warren

A 17-year-old San Diego native, Willy Warren is a baseball fan at heart who created High Leverage Baseball, a public baseball media account covering around-the-league statistical analysis and breakdowns on X. Willy is set to attend the Cronkite School of Journalism in the fall of 2026 at Arizona State University, where he’ll pursue a major in sports journalism.