Seattle Mariners Starting Pitcher George Kirby Set to Take Major Step in Recovery

The Seattle Mariners starting rotation hasn't been at full strength since the season began.

The Mariners have been without 2023 All-Star George Kirby for the entire year due to right shoulder inflammation. He was shut down in spring training on March 7 and has been out since.

Kirby has been down in Arizona rehabilitating his shoulder. In his stead, Seattle has called up Luis F. Castillo and Emerson Hancock for five total starts, or has re-slotted the rotation to avoid the fifth start entirely.

Per a recent report from MLB.com writer Daniel Kramer, Kirby is due to take a major step in his recovery.

The Mariners will return home after a nine-game road trip on April 25 for a series against the Miami Marlins. Per Kramer's report, Kirby is scheduled to throw a live bullpen session at T-Mobile Park.

The report said that Kirby's live BP is "written in pencil," and he will have to meet several requirements before he completes his first live throwing session in Seattle since getting injured.

Kirby was originally anticipated for a return in late April, but Mariners general manager Justin Hollander said that timeline is "optimistic" in an injury update during the team's last homestead earlier this month. A return in May or June is more likely.

If Kirby does continue to clear the necessary benchmarks and the live BP goes well, the next step would likely be for him to be on a rehab assignment with one of Seattle's minor league clubs.

Kirby had a 3.53 ERA with 179 strikeouts in 191 innings pitched across 33 starts in 2024.