Seattle Mariners Starting Pitcher George Kirby Makes First Rehab Start With Triple-A

The 2023 All-Star pitched in his first game in nearly two months on Sunday with the Tacoma Rainiers.

Seattle Mariners starting pitcher George Kirby throws during a game against the Oakland Athletics on Sept. 4 at Oakland Coliseum. | Eakin Howard-Imagn Images

The Seattle Mariners starting rotation is nearing full strength.

Former All-Star George Kirby has been out since March 7 due to right shoulder inflammation. He began the season on the 15-day injured list.

Kirby officially began his rehab assignment with the Triple-A Tacoma Rainiers on Sunday. He pitched three innings in a 6-4 loss against the Las Vegas Aviators. In his first rehab start, Kirby struck out four batters and allowed one earned run off one home run. He threw 42 pitches .

George Kirby looked great in his first rehab start. Final line: 3IP, 1H, 1R, 0BB, 4K. 42 pitches, 33 strikes. pic.twitter.com/y1OZOkexYG

— Mariners Minors (@MiLBMariners) May 4, 2025

Kirby is expected to make one to two more rehab starts before getting activated off the injured list. He'll have his pitch count increase each start in Tacoma and will steadily be ramped back up when he's activated off the injured list.

This is the first sustained injury of Kirby's career. He's pitched through typical soreness and inflammation since he made his major league debut in 2022, but has never spent time on IL before this season.

Kirby is considered one of the best command pitchers in the league. He had a 3.53 ERA in 2024 with 179 strikeouts in 191 innings pitched across 33 starts. He hasn't had a season ERA above that mark in his four-year career.

Seattle has had a bad draw with injuries this season. In addition to Kirby, ace Logan Gilbert was placed on the 15-day injured list due to a Grade 1 right elbow flexor strain. President of baseball operations Jerry Dipoto has said that the team expects Kirby and Gilbert to return by the end of May.

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