HOUSTON -- The Mariners will ride their star rookie pitcher into their first home playoff game in 21 years, as George Kirby is set to start for Seattle in Saturday’s Game 3 of the AL Division Series.

It’ll be exactly one week since his last outing, the rookie's first appearance this postseason, when he earned the save in the series-clinching win last Saturday in Toronto, his first relief outing since 2019 with Single-A Everett.

“It will be great to see how the stadium's filled up, the crowd,” Kirby said Thursday of the atmosphere at T-Mobile Park. “I'm just really ... super grateful to get that start and bring some playoff baseball back to Seattle.”

Considering Robbie Ray’s ongoing struggles against the Astros -- which continued with a stunning walk-off homer to Yordan Alvarez on Tuesday -- the Mariners had long opted to re-add Kirby to the rotation for this best-of-five round.

“I'm super excited, especially going up against the Astros,” Kirby said. “I'm ready to compete. And, yeah, I dreamed about this as a kid watching games. Honestly, I never thought it would come true, but I'm glad I'm here, and I worked hard for it, so glad Skip gave me the ball for Game 3.”

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Kirby made just one start against the Astros, in Houston on July 31, when he battled with command early and lasted just four innings, over which he gave up two runs on four hits, one walk and one hit batter while striking out seven. He labored while uncharacteristically veering from the strike zone, which led to just four whiffs over 74 pitches. He was also on a shorter leash after Mariners reeled him back ahead of the All-Star break to curb his workload.

“I'm still going to be trying to throw strikes as much as I can, but I think it's going to be more quality, strategic strikes,” Kirby said. “Try to hit the corners more often, get in the zone early. That way, I can use my off-speed late in the count. Just try and keep 'em off balance -- [because] when they get a guy on base, they're swinging. They're looking to get that guy in. So I’ve just got to do what I can to limit some good swings.”

For the season, Kirby had a 3.39 ERA and the Mariners went 16-9 in his starts, and he was particularly dominant in the second half until the final two weeks of the season, when his stuff diminished some, and it became clearer that Logan Gilbert would be Seattle’s preference for its third spot in the rotation. Including the one-inning save and six outings in the Minors, Kirby has thrown 157 2/3 innings this year, more than double his 67 2/3 last year.

“I think I've been doing just a great job of recovering during the week, focusing on my breathing, and just trying to get ready for each start or bullpen appearance,” Kirby said. “Yeah, it's definitely a lot more than I've ever thrown before. I felt it in certain starts, but I've been able to find that last bit of energy when I needed it. My body's been feeling great, so I'm ready to keep going.”

Yet Kirby’s velocity ticked up massively in Saturday’s relief outing, fueled by adrenaline. Both his fastballs were up by 2.3 mph or more and his slider was up 2.8 mph. He joked after that he felt he could have thrown 105 mph.

“It wasn't a whole lot different,” Kirby said of adjusting his routine the past two weeks. “I've done it before, it's just been a while. It was actually kind of cool to be back in that situation.”

Kirby will start opposite Lance McCullers Jr., who was sidelined with a right forearm strain through July, by which point the Mariners and Astros had wrapped their regular-season meetings. The spin specialist has been particularly dominant against the Mariners, with a 10-3 record and 2.80 ERA over 18 starts against them, holding their hitters to a .202/.288/.337 (.625 OPS) slash line in 103 innings.

The Mariners, who have struggled to hit breaking pitches this season, will have their work cut out for them -- but they’ll also have their prized righty to counter.

“With everything that's going to be thrown upon him, you’ve got to lean on young guys,” Servais said. “Those are the guys who got us here, so why not. I have a ton of confidence in him. Our whole coaching staff does. Our whole team does.”