Mariners indefinitely shut down Matt Brash's rehab

Mariners right-hander Matt Brash has been shut down indefinitely from his rehab process, GM Justin Hollander told reporters this evening (including Ryan Divish of The Seattle Times). The righty had thrown yesterday ahead of a rehab assignment that was expected to begin this weekend, though now he’ll visit Dr. Keith Meister to determine the next steps.

Brash, 26 next month, was shut down due to elbow inflammation early in Spring Training amid concerns that he may miss the entire 2024 season. Following his diagnosis with elbow inflammation, however, Brash was cleared to resume throwing in early March and has been rehabbing the injury ever since. Per Hollander, that injury has taken a turn for the worse in recent days as he’s begun to feel “tightness” in the aftermath of bullpen sessions that have begun to last longer after each throwing session.

The ominous update is a potentially brutal blow for the Seattle bullpen, which has been without Brash and fellow set-up man Gregory Santos all season. Brash made his debut with the Mariners as a starter back in 2022 but struggled in the role and was quickly moved to the bullpen, where he’s been nothing short of dominant ever since. Across 112 relief innings in his career, the flamethrower has posted a sterling 2.84 ERA with an even better 2.18 FIP eye-popping 34.5% strikeout rate in 101 1/3 innings of work. That’s good for the ninth-highest strikeout rate and second-lowest FIP of any reliever with at least 80 innings of work over the past two seasons.

Given Brash’s utter dominance out of the bullpen throughout his career, he was all but certain to act as the primary set-up man to closer Andres Munoz this season, forming perhaps the strongest one-two punch of relievers in the majors. Those plans will have to be put on hold for an uncertain amount of time, however, with Brash expected to meet with Meister for the second time this season in the coming days. Seattle has relied on Ryne Stanek and Gabe Speier to set up for Munoz in the absence of Brash and Santos.

While elbow issues of any kind bring to mind the possibility of Tommy John surgery for many fans, there’s been no indication of damage to Brash’s UCL to this point, however, and it won’t be clear exactly what the prognosis is for Brash and what his timetable for return could look like until he meets with Meister. With all that said, it seems fair to expect the Mariners to be without their top set-up man for quite some time given the right-hander’s difficulties bouncing back between throwing sessions nearly two months after being cleared to resume a throwing program.

If there’s any silver lining for Mariners fans, it’s that the club’s bullpen has been performing just fine even without Brash in the mix. Seattle relievers rank first in the majors with a 2.40 ERA this season while they rank eighth with a 24.9% strikeout rate and ninth with a 3.68 FIP. That strong performance has involved almost universally solid numbers from the club’s relief corps: among the 11 players the club has used out of the bullpen so far this season, only right-hander Collin Snider and infielder Josh Rojas (the latter of whom pitched in a pair of blowout games early in the season) have posted an ERA above 3.09 entering play today. If the club’s relief corps can remain even close to that effective in the coming months, it’s possible the Mariners won’t miss Brash as much as it might seem on the surface even in the event of an extended absence.