With the 2025 Texas Rangers season having come to an end, we shall be, over the course of the offseason, taking a look at every player who appeared in a major league game for the Texas Rangers in 2025.
Today we are looking at pitcher Kumar Rocker.
There were a number of individual disappointing seasons for the Texas Rangers in 2025. I’m not sure any of them, however, were as disappointing as Kumar Rocker’s 2025 campaign.
Remember how hyped we were about Rocker at the end of 2024? Returning from Tommy
John surgery and destroying AA and AAA batters — 3 runs allowed in 29.2 IP, 47 of 106 batters fanned, just four walks. Making his major league debut in Seattle and getting 17 swinging strikes on 74 pitches while striking out seven and allowing one run in four innings, followed by a couple of decent, if not as dominant, outings to finish the season.
Rocker entered 2025 as a consensus top 50 prospect, with Baseball America having him at #20 overall, and injury concerns being the main reason he wasn’t a consensus top 20-25 prospect. It seemed like he was ready to step into a major league rotation and immediately contribute, while offering the ceiling of a legitimate top of the rotation starter. Rocker seemed especially impressive in contrast to fellow Vandy Boy Jack Leiter, who seemed completely overmatched in the majors in 2024.
Rocker was not, as it turned out, ready to step into a major league rotation and immediately contribute in 2025.
Rocker did start the season in the rotation, out of necessity as much as anything else after a rough spring. His first start of the year was in Cincinnati. Four batters into the bottom of the first he was down 3-0 after a single-homer-single-stolen base-double sequence. He bounced back to get the next three batters, and could have gotten out of the second without allowing a run if he could have retired Matt McLain, who had hit the homer off of him in the first. McLain drew a seven pitch walk, however, and then Elly De La Cruz took Rocker’s next pitch deep for the momentum-shifting two out, three run homer. Rocker allowed a single and a walk after that, then retired the final four batters he faced, two on strikes.
It was a microcosm of what we would see from Rocker in 2025 — inefficiency, an inability to control the opponent’s running game, some ugly results, and some instances where he looked great, where you are left wondering why he isn’t performing at that high level more often.
Rocker made five starts with the Rangers before landing on the injured list with a shoulder impingement after a 1.2 inning, five run outing in Oakland. After a two game rehab assignment — one for Frisco, one for Round Rock — that saw Rocker again dominate minor leaguers, allowing 2 hits and 1 walk in seven shutout innings while striking out eight, the Rangers activated him and returned him to the rotation.
That return lasted just one start. You probably remember it — it was the game where Rocker got Jake Mangrum to hit what should have been an inning-ending ground out to first base, but Rocker didn’t cover first base, resulting in a pair of runs scoring to turn what was a 3-0 Rays lead into a 5-0 Rays lead in a game the Rangers ultimately lost 5-4.
Rocker was optioned the next day, with the plan for him to get innings for a while in Round Rock. He only made one start for the Express, though, before Tyler Mahle went to the i.l. with a rotator cuff strain, creating a hole that Rocker was brought back up to fill.
Rocker made eight more starts upon his return, and was better, superficially at least — he had a 3.95 ERA and 4.96 FIP in 41 innings, compared to an 8.87 ERA and 4.72 FIP in his first six starts of the year. His first start back saw him throw five shutout innings against the ChiSox, with six Ks against just one walk. He also had a start in July where he allowed one hit in 6.1 shutout innings against Detroit.
He continued to struggle to work deep into games, however, as he struggled to put away batters and keep his pitch counts down. And basestealers continued to be an issue for him — he allowed 11 stolen bases in 11 attempts in 2025.
Rocker’s last game in the bigs in 2025 was on July 31 — the addition of Merrill Kelly allowed the Rangers to return Rocker to AAA. He made one start for Round Rock after being sent down, then didn’t pitch again until mid-September, with the team having him work on things on the side while also seeking to limit his innings.
Kumar Rocker is really a mystery at this point, with moments where he appears elite and moments where he looks like he isn’t a major leaguer. Part of the overall inconsistency can probably be chalked up to his overall lack of innings — from his freshman season at Vanderbilt in 2019 through the end of the 2025 season Rocker has accumulated just 430.1 innings, due to a combination of the pandemic, not signing with the Mets after they drafted him in 2021, and Tommy John surgery. One of the things Bruce Bochy talked about last year, in the context of controlling the running game and the mental error on not covering first, is that Rocker is much more inexperienced from an in-game action standpoint that most pitchers of his age and ability.
Rocker’s slider is an out pitch, a legitimate weapon, and his cutter and curveball can be quality pitches as well, though his command of his curveball is too erratic for it to be something he can rely upon. However, his fastball and sinker, despite averaging in the 95-96 mph range, were pounded in 2025. His fastball is unusual, in that it lacks vertical movement but has a lot of horizontal movement — from a movement standpoint, his sinker is the more effective pitch.
The result is that Rocker isn’t generating many swings and misses with his fastball or his sinker. That’s less of an issue with the sinker, which isn’t generally a swing-and-miss pitch, than the fastball, and it may be that Rocker would be better off using his sinker as his primary fastball while using the fastball as an occasional show-me pitch. That said, he will have to command his sinker better to have success that way.
Rocker finished the 2025 season with a 5.74 ERA, a 5.74 xERA (convenient!), and a 4.88 FIP. He’s a ground ball pitcher — he was in the 80th percentile in 2025 in ground ball rate, and his ground ball rates in the minors were even higher — so should benefit from what we expect will be a good Rangers’ infield defense in 2026, though one could say the same about 2025, when the Rangers had one of the best infield defenses in the league.
Rocker appears to have a good chance of opening the 2026 season in the rotation once again, with manager Skip Schumaker calling his most recent outing “electric” (shades of Jamey Wright, I know). Jack Leiter took a step forward in 2025, after getting knocked around in 2024. Fingers crossed that his Vanderbilt teammate can do the same this year.
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