Mariners' Rotation Takes Hit With George Kirby Set to Miss Start of 2025 Season
Houston, Texas, USA. 25th Sep, 2024. Seattle Mariners pitcher George Kirby (68) throws a pitch during the Major League Baseball game between the Seattle Mariners and the Houston Astros at Minute Maid Park in Houston, Texas. Seattle defeated Houston 8-1. Credit Image: © Prentice C. James/Cal Sport Media
The Seattle Mariners are going to rely on the strength and depth of their rotation as much — if not more — than any team in baseball this upcoming season as they aim to get back to the postseason in the AL West.
The depth of that starting group will have to face an unexpected early test, however.
Speaking at the team’s spring training complex, Mariners general manager Justin Hollander told reporters from Arizona on Friday that starter George Kirby will likely begin the season on the 15-day injured list. The right-handed hurler wants to continue pitching, but Hollander said that the 27-year-old “lost that argument” with the team protecting the player from himself.
The good news for Seattle, Kirby, and Mariners fans is that he’s already undergone an MRI and according to Hollander, it revealed “zero structural damage.” What was revealed was the inflammation in the right shoulder, which means Kirby needs time to rest for that inflammation to subside.
The bad news, however, is that Hollander called Kirby’s absence a week-to-week issue rather than a day-to-day one. This means Kirby will likely miss more than a couple of outings while he’s on the shelf, and Hollander was quick to point out how important it was for the talented hurler to be healthy for the team in the long-term over taking chances with him in the early portion of the campaign.
The question now, of course, is what this means for Seattle’s rotation. The answer seems to be pretty obvious, but it’s worth repeating. Logan Gilbert, Luis Castillo, Bryan Woo. and Bryce Miller are locked into starting spots, and that was going to be the case whether Kirby was ready to start 2025 or not. It’s likely that one of Miller or Woo moves up a spot in the rotation to begin the year, but the order doesn’t really matter so much.
As for who takes Kirby’s place to begin the year, there’s a couple of potential options, but only one seems realistic. Emerson Hancock has been penciled in as the sixth starter for the Mariners, and now he’ll all but assuredly be the fifth option for Seattle to begin the year. Hancock is not of the quality of the names listed above, but consider that more compliment to the “big four” rather than an insult to him. The metrics are not pretty — Hancock ranked in the bottom fourth percentile in categories like hard hit percentage (46 percent), expected batting average (.290), and strikeout percentage (14.7) last season, but outside of one disastrous start against the Rockies where he gave up eight runs in 3 1/3 innings, he held his own as a rookie in 2024.
The Mariners also have Jhonathan Diaz and a few others who are capable of making starts, but none of those names seem likely to usurp Hancock as the team’s fifth starter to open the season. The majority of their top pitching prospects are at the lower levels, and it wouldn’t make sense to rush one of those arms up under such circumstances.
The other plausible option for Seattle would be to skip a fifth starter when possible, but that doesn’t seem likely. The Mariners have been very cautious in protecting young arms — that’s one of the reasons Kirby is hitting the injured list even with no structural damage — and while the team does have a few off days in the early portion of April, it’s more likely Seattle gives arms like Castillo, Gilbert, and the rest of the group an extra day rather than push them to begin the season. A trade could also explored if Seattle believes Kirby is going to miss substantial time, but Hancock should be expected to receive at least a handful of starts to prove himself before exploring outside alternatives.
Obviously, it’s not ideal to have Kirby miss time. He’s one of the most talented young command artists in baseball and Seattle’s mediocre offense and volatile bullpen make weakening the rotation a less-than-ideal start to the 2025 campaign. But fortunately, this doesn’t appear to be a long-term issue, and the quality of the rest of the rotation and just-enough faith in Hancock make this less of a problem than it could be for some other clubs in the American League.