FanGraphs Predicts Drop-Off For Young Seattle Mariners Starter Bryce Miller
The Seattle Mariners have arguably the best starting rotation in baseball.
The collection of Logan Gilbert, George Kirby, Luis Castillo, Bryce Miller and Bryan Woo all had sub-3.70 ERAs in 2024. It was the only rotation to have four pitchers start 30 or more games.
The five are under team control for several more seasons and Castillo, who's the only one of the group not drafted and developed by Seattle, is the only one who'll make eight figures in 2025 ($24.15 million).
The combination of team control and collective low-cost has afforded the Mariners the opportunity to potentially try out one of their best starting pitching prospects, Brandyn Garcia, in the bullpen in 2025 — per a story from the Seattle Times' Adam Jude.
If there are any legs to the rumors that the organization is a legitimate contender to land Japanese hurler Roki Sasaki, then the rotation really will be an embarrassment of riches in 2025.
But as it stands, the returning five from 2024 will be highly-regarded on Opening Day on March 27, 2025.
Which makes it surprising that popular website, FanGraphs, has arguably Seattle's most promising hurler taking a step back next year.
Miller had the best season among the Mariners starting pitchers on paper. The former Texas A&M Aggie finished the year with a 2.94 ERA with 171 strikeouts in 180.1 innings pitched and a 0.98 WHIP across 31 starts.
Bryce Miller, 87mph Splitter (ball) and 96mph Two Seamer (backwards K), Individual Pitches + Overlay pic.twitter.com/VAhjU7KWul
— Rob Friedman (@PitchingNinja) September 19, 2024
FanGraphs' 2025 ZiPS Projection model has Miller finishing with the second-lowest fWAR (FanGraphs WAR) on the rotation at 2.8 — behind Gilbert (4.0), Kirby (3.5) and Castillo (3.3).
The model projects Miller to have a 3.63 ERA in 2025 with 139 strikeouts across 159 innings pitched and 29 starts.
On the surface, it's easy to see the reasoning for a potential regression from Miller. He has the most diverse arsenal of throws in the rotation aside from Gilbert, but struggled at times to implement it. If those struggles continue, he could regress.
In the same breath, his diverse arsenal paid dividends overall when he was on top of his game. The only pitch that hitters had at least a .250 average against was his cutter, per Baseball Savant. He threw that pitch just 63 times — the least amount in his arsenal.
Miller is a sponge and takes a little bit of everything from his fellow starters. A full offseason to refine his selection of offerings can lead to a season in the same vein of the one he had in 2024. Or it could lead to less options and hitters having a better idea of what they're going against, leading to a season like FanGraphs predicts.
Miller's potential makes him one of the most intriguing Seattle players to watch in 2025. And it will be interesting to see whether he makes strides or loses ground.
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