The Seattle Mariners figure to have one of the best starting pitching rotations for several years to come.

The combination of Logan Gilbert, George Kirby, Luis Castillo, Bryce MIller and Bryan Woo are all under team control for multiple seasons. Kirby, Gilbert and Castillo have made All-Star games and Woo and Miller just finished their second major league seasons.

Seattle is also well-positioned to have pitchers step up in case of injury or trade; Pitchers like Brandyn Garcia, Logan Evans and Emerson Hancock are now in the upper minors.

The rotation was the only one in the majors to have four pitchers start 30 or more games in 2024. It also led the league in total quality starts. Every member of the rotation finished with ERAs below 3.70.

Despite these accomplishments, popular baseball website FanGraphs has the rotation slightly regressing in 2025, per its ZiPS projections model.

The model has Gilbert putting up similar numbers in 2025 that he had in 2024. Inversely, the model has Woo and Miller taking steps back in 2025.

Seattle still projects to have the second-best rotation in the MLB behind the Philadelphia Phillies, and the best in the American League. Gilbert maintaining his status as the ace of the staff plays a part in that. But so does a predicted return to All-Star form for Kirby.

Kirby made the first All-Star game of his career in 2023. He had a 3.35 ERA with 172 strikeouts in 190.2 innings pitched across 31 starts that season.

Kirby was still a great starter in 2024, but his numbers did inflate slightly. In 2024, he had a career-high 3.53 ERA and fanned 179 hitters in 191 innings pitched and 33 starts.

FanGraphs predicts Kirby’s numbers in 2025 will compare well with his statistics in 2023.

Per the model, Kirby will finish with a 3.32 ERA and 162 strikeouts in 173 innings pitched across 30 starts. The model also has him finishing with a 3.5 fWAR (FanGraphs WAR). That number is the second-highest on the staff behind Gilbert’s 4.0 fWAR.

Kirby is one of the better command-pitchers in the majors. Out of his six-pitch arsenal, the only pitches that hitters averaged better than .253 against were his sinker and knuckle curve, according to Baseball Savant. He had a 21.7% put-away rate with his fastball and a 22.6% put-away rate with his slider.

Kirby had a streak of nine consecutive quality starts from June 9-July 26, but the last two months of the year exacerbated his numbers. He had a 3.80 ERA over his last seven starts of the season and a 4.02 ERA over his last 15.

If Kirby can sustain his June/July form over the whole year, a return to the All-Star game will definitely be on the table for the former Elon College hurler.

FANGRAPHS PREDICTS DROP-OFF IN 2025 FROM YOUNG PITCHER: Former Texas A&M pitcher Bryce Miller could take a step back in 2025, per the website FanGraphs’ ZiPS Projections model. CLICK HERE

VETERAN MARINERS PITCHER INVOLVED IN INTERESTING MOCK TRADE: Luis Castillo continued to be at the forefront of mock trades, with the latest hypothetical deal taking place between the Seattle Mariners and Boston Red Sox. CLICK HERE

RECENT MARINERS DRAFT PICK COULD DEBUT IN 2025: Former Kansas Jayhawk, and 2024 third-round draft pick Hunter Cranton could factor into the Seattle Mariners bullpen in 2025, per a recent story. CLICK HERE

Continue to follow our Inside the Mariners coverage on social media by liking us on Facebook and by following Teren Kowatsch and Brady Farkas on “X” @Teren_Kowatsch and @wdevradiobrady. You can subscribe to the “Refuse to Lose” podcast by clicking HERE.