SEATTLE -- It’s not just that Matt Brash is being sent down to Triple-A Tacoma on Thursday to sort out his command and mechanical kinks -- he’s also being shifted to the bullpen.

The Mariners made the decision to transition the rookie right-hander following his outing on Wednesday in Houston, where he threw 77 pitches over just three innings and again struggled to stay in the strike zone. It’s been an ongoing challenge for Seattle’s No. 6 prospect and No. 95 overall, per MLB Pipeline, ever since he won the No. 5 rotation spot out of Spring Training.

“It really comes back to command,” Mariners manager Scoytt Servais said. “His stuff is certainly capable of getting Major League hitters out. We've seen it when it's on. But you’ve got to throw strikes. You’ve got to throw consistently, and then being able to make adjustments quickly. That's kind of what he struggled with.”

Additionally, the Mariners have not yet determined who will take his spot for his next scheduled turn on Monday, or beyond.

Based on his power profile and two-pitch mix, Brash has the fit for a reliever, but after he skyrocketed up the farm system in 2021 then won the gig in his first big league camp, he seemed to be on a starter trajectory long term. And he still very well could be. The Mariners aren’t saying that this decision is permanent, but rather, the best chance for him to continue impacting the Major League team this season.

Yet because it’s a significant transition, Brash’s development in that role is likely a matter of weeks to months and not shorter term.

The Mariners made a similar transition to Brash’s in early 2016 with Edwin Díaz, who went on to become an All-Star and he set Seattle’s single-season franchise record with 57 saves in 2018. But he shifted to the ‘pen a full month before he reached the Majors, and he’s stayed there since and is now one of the game’s elite closers for the Mets.

“When he first got here, Edwin Díaz was a starter," Servais said. "We transitioned him into the bullpen for probably a three- to four-week period in different situations, so he gets a feel for what works for him as far as warming up and then coming into the game with a clean inning. Go out, come in, pitch a couple innings, come in with runners on base. You can kind of orchestrate all that in the Minor Leagues.”

In years past, as the club was navigating its rebuild and assessing young, unproven talent, there was more of a leash for those players to sort out their issues at this level. Justin Dunn and Justus Sheffield were the most notable such examples among starting pitchers. But with a pointed objective to win now, there’s more urgency.

“I definitely think he's a guy that can help us win games this year,” Servais said. “I just think the chance to impact our team is probably greatest if he can assimilate to the bullpen and come out and help us there on multiple days in a week versus just one day in a week.”

Brash is one of three Mariners pitching prospects among MLB Pipeline’s Top 100 -- along with right-handers George Kirby (No. 30) and Emerson Hancock (No. 80) -- and he’s the first to reach the Majors. Righty Levi Stoudt is also among their touted pipeline, and it’s expected that both he and Kirby will contribute sooner than later.

That could be as early as Monday.

Kirby battled Brash for a rotation spot in spring, but the club opted to go with Brash in large part due to his higher innings accumulation last season. Kirby has dominated at Double-A Arkansas, with a 1.82 ERA and career-high 34.2% strikeout rate in five starts, all but one of which he’s thrown a strict five innings. When he does reach the Majors, he’ll likely be capped at that amount per outing. Stoudt has also impressed with a 3.46 ERA and 26.7% strikeout rate, and he’s been stretched out to six innings.

“We’ve got some ideas,” Servais said. “We don’t have to make that call today.”