Who would start Game 5 of the American League Division Series for the Seattle Mariners has been a widely debated topic among the fan base.

The Mariners had options with Game 1 starter George Kirby due up next but Game 2 starter Luis Castillo also available on regular rest. Both pitched well in their outings earlier in the Division Series against the Tigers, and both have experience in starting elimination games.

Castillo threw 5 1/3 innings of one-run ball in the Reds’ 2020 National League wild card game, and Kirby started the 18-inning Game 3 of the ALDS in 2022 for the Mariners, keeping the Astros off the board for seven innings. In the wild card series the week before, Kirby pitched out of the bullpen, picking up the save in the 10-9 deciding win over the Blue Jays.

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Assuming both could be used, Kirby would seem the best option out of the ‘pen as he has done it before. His stuff following Castillo could perhaps play up more. It seemed an intriguing option to debate, but the Mariners chose not to overcook the situation and go with Kirby, who not only lined up for the start, but also had an extra day of rest.

“It was kind of by design and this is kind of the way we had hoped it would work out, so this is the way it went,” said manager Dan Wilson, who made the announcement following the Mariners workout Thursday afternoon that Kirby would be the Game 5 starter.

Wilson confirmed it was all hands on deck with Castillo and others to be available out of the bullpen. As for Kirby, while excited about the opportunity to take the ball, he stressed he and the rest of the pitching staff were ready for a game with so much on the line.

“Nothing changes,” he said. “We’re all – this time of the year all pitching with your best stuff. Everything kind of just leads up to this moment. You’ve got all your best stuff going out there and attacking. And I think everyone’s going to do that, and we’ll just try to put up as many zeros as possible.”

These two teams have become quite familiar with each other over the last week, but Kirby isn’t overly concerned facing the Tigers twice in such a short amount of time could be a disadvantage for him.

“You can always switch up game plan, whatnot, but I think it really just comes down to having some conviction in your pitches and executing,” he said. “More times than not, when me or anyone else executes, you get the guy out. So it’s just staying locked in on every pitch, being committed, having some conviction on every pitch, and kind of just leave it all out there.”

Notes

– On the Mariners turning the page quickly and keeping things relatively light in the clubhouse after losing Game 4 in Detroit, Wilson said he was not surprised.

“I think that’s where these guys are,” he said. “They know tomorrow means a lot just like a lot of the games in September did. And so they’ve been through it. They’ve pushed. They know what needs to happen.”

– Unlike the Mariners who flew home Wednesday night, the Tigers elected to fly to Seattle Thursday after a brief workout at Comerica Park.

– Will Bryan Woo be available for the ALCS should the Mariners advance? Woo went through the daily warmups and throwing with his teammates Thursday. He did not throw off a mound but briefly did some flat-ground work with pitching coach Pete Woodworth catching him.

Woo doing some flat ground work throwing to Pete Woodworth. pic.twitter.com/5cz1h01Mfi

— Shannon Drayer (@shannondrayer) October 9, 2025

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