Mariners Could Finally Be Watching One Long-Anticipated Rotation Breakthrough

For as good as George Kirby has already been, it still feels like the bigger conversation around him has never really gone away. The Mariners have always believed he could be capable of becoming one of the truly dominant arms in the league. And this spring feels a little different.

There’s a growing sense that Seattle may finally be staring down the fully realized version of Kirby, the one people inside and outside the organization have been waiting to see for a while now. What’s changing is the feeling that he’s carrying that trademark command, efficiency, and attacking confidence with a little more ease, a little more conviction, and the kind of maturity that unlocks another gear.

5️⃣0️⃣0️⃣ career punchouts for George 👏 #TridentsUp pic.twitter.com/Ik5PtNFuN9
— Seattle Mariners (@Mariners) June 8, 2025

Mariners Could Be Watching George Kirby Unlock a Scary New Gear

That was part of the takeaway from Daniel Kramer of MLB.com, who predicted Kirby to be the Mariners’ top Cy Young contender this season. The reasoning makes plenty of sense. Kramer noted there was a different aura around Kirby this spring, one that teammates and coaches connected to a stronger sense of conviction. He looked more relaxed, even more jovial, which might sound small on the surface, but with a pitcher like Kirby, that kind of internal comfort can matter.

This is the same pitcher they trusted to start the first game of the American League Division Series and then handed the ball again for Game 7 of the American League Championship Series. Teams do not make those kinds of decisions unless they believe they’re giving the ball to somebody built for that stage. Kirby himself admitted how much that belief mattered, saying that having Dan Wilson and the organization trust him in those spots did a lot for his mental game.

The overall career body of work already gives this idea some real weight. Kirby posted a 3.39 ERA as a rookie in 2022, followed that with a 3.35 mark in 2023, then delivered a 3.53 ERA and 1.07 WHIP across 33 starts in 2024. Last season, the 4.21 ERA in 23 starts looked like a step backward on paper, but that doesn’t really tell the full story. He dealt with injuries, never looked fully right for long stretches, and the rhythm just wasn’t consistently there.

If Kirby is healthy for a full season, the baseline expectation should probably be something close to that 2024 form again, which is already a really valuable pitcher. But the real intrigue here is that a lot of people around this team seem to believe even that might not be the ceiling. They believe there’s still another level in there, a nastier one, the kind of season that shifts him from being appreciated in Seattle to being taken a whole lot more seriously across the sport.

They might be right. The Mariners don’t need George Kirby to prove he belongs. He already has. What they may finally be watching now is the season where he turns all of that long-teased potential into something undeniable.