The Rangers officially placed right-hander Tyler Mahle on the 15-day injured list due to right shoulder fatigue. The placement is retroactive to June 12. Right-hander Kumar Rocker was called up from Triple-A and will start for the Rangers today in what was initially Mahle’s turn in the rotation.
The transaction was telegraphed yesterday, when Rocker rejoined the team less than 15 days after he was optioned to Triple-A Round Rock. Such a quick recall could only happen in the event of another injury, and Texas manager Bruce Bochy told MLB.com’s Kennedi Landry and other reporters that Mahle felt some shoulder discomfort during his last start on Tuesday.
This shoulder issue may have contributed to Mahle allowing four earned runs in 5 2/3 innings (though the Rangers still recorded a 16-4 win over the Twins) that night. Mahle has an outstanding 2.34 ERA over 77 innings this season, though eight of the 20 earned runs he has allowed this season have come in his last two starts.
Some regression was probably inevitable anyway for Mahle, whose secondary metrics paint a less flattering view of his performance. Mahle’s 4.56 SIERA is almost twice the size of his 2.34 ERA, as a .253 BABIP and an 82.3% strand rate have helped Mahle get away with below-average strikeout (18.2K%) and walk (8.8BB%) rates. The gap between Mahle’s .263 wOBA and his .330 xwOBA is one of the largest of any starter in baseball. On the plus side, Mahle isn’t allowing much hard contact, and he has allowed only four home runs over his 77 frames.
In the bigger picture, continued shoulder discomfort for Mahle is a particular concern, given how similar shoulder injuries also limited him in both 2022 and 2024. The 2023 season saw Mahle undergo a Tommy John surgery, and he didn’t return to action until August 6 of last year. Given all of these recent injuries, it could be that Mahle is simply a little tired since his 77-inning workload is already beyond the 56 1/3 total innings his threw in the majors and minors over the 2023-24 campaigns.
Mahle joins fellow starters Nathan Eovaldi, Jon Gray, and Cody Bradford on the Texas injured list, leaving the Rangers with a makeshift rotation of Jacob deGrom, Patrick Corbin, Jack Leiter, and now Rocker. Of the injured starters, Bradford may be the closest to returning since he recently threw two simulated innings, though he’ll still need a lengthy rehab assignment after missing the entire season recovering from an elbow sprain.
The Rangers have an off-day on Monday before starting a stretch of 25 games in 27 days heading into the All-Star break. The Texas relief corps has recently stepped up with a pair of impressive bullpen days to help the club patch the holes in the rotation, yet continuing to rely too heavily on the pen obviously isn’t an ideal strategy — especially not heading into such a busy portion of the schedule. Dane Dunning is probably the top experienced option to be recalled from Triple-A to cover some starts and eat some innings, and the Rangers have an opening on their 40-man roster if Dunning’s contract is selected.
There’s an added financial wrinkle to Mahle’s injury, as any time spent on the IL could cost him some significant bonus money. Mahle is set to earn a $500K bonus if he pitches at least 100 innings, and then an $1MM bonus for hitting each of the 110-, 120-, and 130-inning thresholds, and then a final $1.5MM bonus at 140 innings. This extra cash has plenty of implications for both Mahle’s wallet and the Rangers’ attempts to stay under the luxury tax threshold, so a lengthier stay on the injured list has plenty of bigger-picture implications.