Promising Mariners Pitcher Set for Breakout Year

Bryce Miller has been turning heads all off-season. Miller, 26, has pitched 1.2 innings so far this spring, striking out three, not allowing a hit. But the real hype comes from the multiple videos Miller has posted of himself on X, showcasing various pitches he’s been working on during the break.

Miller formed an almost impenetrable one-two duo with other Mariners phenom Bryan Woo at the back end of the Mariners’ rotation in 2024. Miller started the third most games for Seattle, 31, behind George Kirby and Logan Gilbert with 33. In just his second big league season, he finished the year with a 2.89 ERA and 171 strikeouts in 180.1 innings. He put up 3.4 WAR.

With all the eyes on the future of Luis Castillo, Logan Gilbert and his emergence as the ace of the staff, and George Kirby being George Kirby, Miller is in a prime spot to follow up his breakout year.

We’ll likely see a much bigger role from Miller in 2025. Year three seems to be when the Mariners take all the reigns off. Both Gilbert and Kirby experienced increased workloads in their third year, with Gilbert breaking the 30 start mark for the second time and Kirby for the first.

What’s changing for Miller in 2025

According to his savant page, Miller is changing his approach, too. His fastball usage is decreasing. It was down 15.9% in 2024 from 2023, and his split finger usage was up 16.8%, filling those pitches. He also swapped his sweeper for a sinker, with about a 10% difference going either way.

This is something that we’ve seen time and time again from the Seattle pitching lab. The Mariners want their pitchers to emphasize what they do well and do it often, building confidence. Miller needed secondary pitches to get batters out without relying on his fastball. This saw him give up fewer home runs in 2024 despite pitching in 6 more games and 51 innings. His added reliance on breaking pitches did see his walks almost double, but with his increased workload, his BB% was still only 6.4%, 2% lower than the league average.

Miller is looking to sure up an already great rotation and improve on a great 2024.