Where Does George Kirby’s Injury Leave Seattle?

The Mariners have arguably put together the best baseball rotation over the last three seasons. Historically struggling with most aspects of baseball, the Mariners have excelled at pitching throughout the 2020s. The Mariners use a process that they’ve outlined many times of just keeping things simple. Making sure their pitchers play to their strengths to build their confidence. This has led to elite relievers like Paul Sewald, Edwin Diaz, Gabe Speier, Matt Brash, Justin Topa and many more seemingly being plucked out of thin air.

With the lack of success, the Mariners deeply understand how confidence can affect a player’s performance. This is part of what sets their rotation apart. The pitchers play to their strengths: George Kirby and his unique ability to live in the strike zone, Logan Gilbert and his freak-of-nature-like extension, Luis Castillo and his arm angle, and so on.

A League of Their Own

Their ability to stay healthy is the last thing that sets them apart from most rotations. Since the rotation came to be in 2023, Woo is the only pitcher to make less than 25 starts in a season due to spending time on the IL. Despite getting injured, Miller, Kirby, Gilbert, and even Castillo all made 30 or more starts in 2024.

The Mariners Lose One Of Their Best Arms

Going into 2025 that puts the Mariners in a new position with the news of George Kirby likely starting the year on the IL. The right-hander felt tightness in his shoulder after struggling thus far this spring and was immediately shut down. While it’s yet to be made official, major news outlets like the New York Times and even MLB have reported the IL-Stint for Kirby, with Mariners GM Justin Hollander saying “Kirby hasn’t been feeling great after his outings.”

After a lackluster offseason, an injury to one of their best starters incites more disappointment and unrest among fans. But this is to be expected from Seattle. President of Baseball Operations, Jerry Dipoto, has expressed his reluctance to trade his pitching all offseason. Ken Rosenthal of The Athletic made note of teams actively looking for starting pitching, notably leaving the Mariners off the list.

But this shouldn’t come as a surprise to anyone who follows the Mariners.

Who Is Going To Step Up And Help Out?

The Mariners have one of the best “stop-gaps” in baseball. In his limited action, Emerson Hancock hasn’t seen the Major League success of his rotation peers. Despite some injuries, he’s helped keep the Seattle ship afloat. The Mariners have used him as their intermittent rotation spot when injuries have flared up over the past two seasons. 2023 saw Hancock make three starts, giving up six runs in 12.0 innings.

In 2024, Hancock started 12 games for Seattle, giving up 32 runs in 60.2 innings, giving him a 4.50 ERA in 2023, and a 4.75 ERA in 2024. While this is far from the heights of the Kirby’s and the Gilbert’s, this is still a functional arm. Baseball-Reference has the league average ERA for a pitcher at 4.33 in 2023, and 4.07 in 2024.

When you look at other pitchers who have made supplemental starts for Seattle, like Tommy Milone, who has a 4.65 ERA in 32 starts, and Jhonathan Diaz, who has a 4.66 in 9.2 innings, Hancock offers a lot more value and room to grow entering his age 25 season.