After Making Great Strides at Triple-A, Jacob Misiorowski Joins the Brewers Starting Rotation

The wait for Jacob Misiorowski's big-league debut is over. The flame-throwing right-hander has joined the Brewers in Milwaukee and will make his first start on Thursday night against the St. Louis Cardinals.

The fact that Misiorowski will begin his MLB career as a starter is significant. While the Brewers maintained their belief that he could develop into a big-league starter, his ascent through the minors was shrouded in concerns that his high walk rate, inconsistent mechanics (made so by a frame so lanky as to be unwieldy at times), and lack of a fourth pitch would push him to a relief role.

Misiorowski has mitigated some of those concerns this year. He's slightly cut his walk rate, from 14.4% in 2024 to 12.3% in 2025, but more importantly, his percentage of pitches in the strike zone has jumped from 46.4% in Triple-A last year to 51.7% this year.

"He's in the zone a lot more," Pat Murphy said. "Not as many big misses. The counts are better. Just the control in general of who he is. His delivery's a little more compact."

The chief baseball decision-maker for the team agrees.

"The stuff is the stuff, but just the ability to actually execute is now something that he's much more comfortable with," Matt Arnold said. "He's shown us that it's probably the right time."

The 23-year-old also developed his changeup into a bona fide fourth pitch, with solid depth and arm-side fade. Public stuff modeling metrics don't love it, but its separation from his fastball out of the same arm action could help it play up.

The right-hander has also worked deeper into games while maintaining his outstanding stuff. After going six or more innings in just three of 21 starts last year, he's already done it four times in 12 starts this season. He garnered attention last month for hitting 103 mph with his 78th pitch of his May 15 start.

That's not to say Misiorowski is a finished product. His control evaded him two outings ago, when he issued six walks in a two-inning start on May 31. However, he's largely looked ready to start at the game's highest level for several weeks, something that couldn't be said last year—or even in spring training. The next steps in his development can only be taken by learning from facing big-league hitters.

"I think you see it with some of the young guys that we've seen here, whether it's [Chad Patrick] or [Logan Henderson] or [Quinn Priester]," Arnold said. "Continuing to overcome some adversity and show that they can do that at the highest level is the ultimate challenge. I think he's ready for that."

Part of the timing decision was that, once Misiorowski demonstrated his readiness for the challenge, the team wanted to reward the progress immediately.

"When you have an entity like this, you might be wasting bullets (in the minor leagues) if you don't bring them up soon," Murphy said.

Unlike Henderson's sporadic cups of coffee in the majors, Misiorowski's first promotion is not expected to be a one-and-done start. The Brewers plan to make him a full-time member of what was already a full starting rotation. Under the 13-pitcher limit, a six-man rotation would leave the club shorthanded in the bullpen, so it is moving Aaron Civale to a long relief role for now.

The veteran has started every game of his big-league career, and the change comes during his platform year in free agency. With those factors in mind, Murphy acknowledged that Civale is "not happy" with his new role.

"It's a big move for him," he said. "It's not necessarily that he hasn't been pitching well, because he has been, it's just that we think he's the best candidate to be able to [pitch in relief] right now."

Civale is a capable starter, but with Misiorowski in the fold and the other members of a suddenly deep rotation pitching well, his limitations make him the odd man out. Murphy has noted that his struggles in his third turn through an opposing lineup restrict him to shorter outings. Last year, opponents posted an .856 OPS the third and fourth times through, compared to a .732 OPS the first two times through. They've gone 4-for-8 the third time through to begin this year.

"You look at his third-time-around numbers, he might be better suited on this year's team right now, to disrupt everything less, if he can be in that long relief role," Murphy said.

The Brewers declined to comment on trade speculation, but as a pending free agent, Civale already appeared to be a potential midseason trade candidate. His downgraded status on the depth chart adds fuel to those speculative flames. Misiorowski, meanwhile, has upside as a spark for this year's team and a potential linchpin of future Milwaukee pitching staffs. After the growth he's shown this spring, he's earned this opportunity.