Mariners overthink starting rotation for ALDS vs. Tigers to a dangerous degree

On Friday, the Seattle Mariners revealed how they're going to begin their starting rotation for the first two games of the American League Division Series opposite the Detroit Tigers at T-Mobile Park. And whatever you thought the answer was going to be, this likely isn't it.

It will be George Kirby in Game 1 on Saturday, followed by Luis Castillo in Game 2 on Sunday. The player known as "TBD" is slotted for the other three games, though the arrangement for the first two games plus Bryan Woo's slow recovery from pec tightness leaves little doubt that it will be Logan Gilbert in Game 3.

Once it became apparent that Woo would not be good to go for Game 1, we assessed the Mariners' options and concluded that their best way forward involved using Gilbert in Game 1, followed by either Kirby or Castillo in Game 2. However, Jerry Dipoto, Dan Wilson and the rest of the brass clearly had other ideas.

Mariners choose a defensible, but dangerous ALDS rotation

At least you can see the logic here, for which it helps that Wilson pretty much spelled it out for the media. As noted by Adam Jude of the Seattle Times, the home/road splits for Kirby and Castillo played into the decision, and they are indeed notable:

• George Kirby: 3.38 ERA at home, 5.16 ERA on the road
• Luis Castillo: 2.60 ERA at home, 4.71 ERA on the road

One also wonders if the Mariners believe Kirby and Castillo to have Big Game Energy. Both of them shoved when Seattle was last in the playoffs in 2022, with Castillo logging two separate seven-inning performances and Kirby throwing seven scoreless innings in his lone start in Game 3 of the ALDS — the less said about how that game ended, the better.

Though Gilbert had dramatic home/road splits in his own right (2.24 ERA at home, 4.74 ERA on the road) this year, his ability to miss bats was one thing that traveled well. He struck out 26.2 percent of the batters he faced on the road, good for seventh among qualified AL hurlers.

One danger here, however, is that leaving Gilbert until Game 3 pretty much dooms him to make only one start in this series. Whatever that is, it's not riding the hot hand. The 28-year-old righty was excellent in his last seven starts of the regular season, posting a 2.52 ERA and fanning 30.2 percent of the batters he faced.

Another danger involves Tarik Skubal, who could end up pitching twice in the series.

Though the Mariners have some recent ownage on the 2024 AL Cy Young Award winner, it will be hard enough to get to him once in this series, much less twice. After going in Game 1 of the Wild Card Series on Tuesday, he's lined up to pitch in Game 2 on Sunday and a potential Game 5 on Friday, with four days of rest in both cases.

Granted, the Tigers tried to avoid throwing Skubal on four days of rest this year, and his splits suggest that was the right call. Yet it's all relative, as he had a 2.58 ERA with a 39.2 strikeout percentage even when he did have to pitch on four days' rest.

In choosing the rotation that they did, the Mariners have set themselves up to counter Skubal with Castillo in Game 2 and again in a potential Game 5. That would have been a fun matchup three years ago. But with Castillo's fastball and strikeout rate past their prime, it's hard to say that now.

The short version is that the playoffs haven't even started yet, and Mariners fans already have cause to sweat a little. There will be crow to eat if this unexpected rotation works out, but it sure feels like a Franken-rotation derived from a room full of people overthinking it.