The Mariners have shut down reliever Matt Brash, per Ryan Divish of The Seattle Times. Brash has been on the injured list retroactive to June 9th with a right lat strain, and a recent MRI showed more inflammation in that area, though he has no structural damage. The righty won’t throw for eight weeks, so he’s officially out for the season. He should be ready for a normal offseason throwing program, per Divish.

When healthy, Brash has been a quality reliever for the Mariners dating back to 2023. He tossed over 70 innings that year while allowing 3.06 earned runs per nine. He walked a few too many hitters but more than compensated for the free passes by striking out 34.7% of opposing hitters and keeping the ball on the ground. Opponents were batting an unusually high .380 off of Brash that year, so there’s an argument that he was even better than the 3.06 ERA.

Tommy John surgery wiped out Brash’s 2024 season and delayed his start to 2025 by a month. When he returned that May, he picked up right where he’d left off. In 53 appearances, Brash held opponents to a career-best 2.47 ERA and induced grounders at a staggering 54.7% clip. The latter mark put him in the top 10% of relievers with at least 40 innings. While his fastball velocity was down over 2.0 mph from his 2023 levels, ERA estimators like xERA (3.25) and SIERA (2.99) pegged Brash as more or less the same pitcher as he was pre-surgery.

The righty’s limited work in 2026 has been serviceable, if a clear step back from 2025. Brash has held opponents to an ERA of 0.54 in 16 2/3 frames, but his 4.21 xERA and 3.71 SIERA are much less impressive. He’s shown good control as always, but his strikeout rate has gone from dominant to merely slightly above average at 23.4%, while Brash’s 41.0% grounder rate now checks in a hair below average.

The decline in Brash’s rate stats can probably be chalked up to his injuries. He missed three weeks with lat inflammation in May before returning on May 20th. After six more appearances, he went on the IL again for the lat strain, and he’s been out ever since. Seattle transferred Brash to the 60-day IL when they activated Carlos Vargas on August 21st. Having missed more than 60 days, Brash was technically eligible to return any time, but now, he’s decisively out until 2027.

Brash’s shut-down isn’t exactly a surprise, but it’s nonetheless a blow to a Mariners bullpen that sure could use the help. Seattle’s relievers rank 24th in the Majors with a 4.51 season ERA. It’s been even worse since the start of August. In over 100 innings since August 1st, Mariners relievers have allowed nearly eight earned runs per nine, easily worst in the league. Closer Andrés Muñoz, deadline pickup Seranthony Domínguez, and three others have thrown at least 12 innings with ERAs over 4.50 in that span.

Muñoz has given up three home runs in his last 12 innings after allowing four in over 38 innings before that. As a matter of fact, the bullpen as a whole has struggled with the long ball, as they’re the only group in the Majors allowing more than two home runs per nine since the start of August. If Brash had returned and picked up his old ground ball tendencies, he would have helped significantly in that regard. Instead, the M’s will simply hope for turnarounds from their existing arms as they close out a season in which they’re increasingly unlikely to make the playoffs.

Brash came into the season with over three years of service time and has since crossed the four year threshold. Seattle controls him for two more arbitration seasons before he hits free agency in 2029. With how much time he’s missed, Brash will only get a modest raise for 2027.

Photo courtesy of Daniel Kucin Jr., Imagn Images (via Reuters Connect)