MINNEAPOLIS -- Alex Kirilloff is known to be a stoic person -- to say the least. Even when Twins manager Rocco Baldelli phoned Kirilloff, the organization's No. 2 prospect, on Monday night to inform him of his callup to the Major Leagues, the 22-year-old outfielder didn't break character.

"I chatted with him for a little while and then also happened to mention that he’s going to make our playoff roster, and the tone on the other end of the line did not change a ton," Baldelli said. "I think he said, ‘Oh yeah? That’s awesome.’ And that was essentially it."

And now, Kirilloff is in Wednesday's lineup, batting sixth and playing right field. He makes history as just the third player since the first World Series in 1903 to make his Major League debut in the postseason. He joins Mark Kiger, who played in two games for the A's in the 2006 American League Championship Series, and Adalberto Mondesi, who had one at-bat for the Royals in the 2015 World Series.

But of the three, Kirilloff is the only one to start in his debut, making this an all-time first.

Kirilloff insists that he is, in fact, excited to be on the Twins' active roster for the AL Wild Card Series against the Astros. The outfielder and first baseman hasn't played a day above Double-A and never got a callup to the Majors in 2020. Now, he's in the lineup.

"First and foremost, I think it’s awesome for him to get that opportunity," said Randy Dobnak, who grew up in the same area as Kirilloff in Pittsburgh and knew of him. "He’s worked his butt off.

"Maybe the pitching’s a little different than what he’s used to, but I think he’s a really great hitter. He’s a really smart baseball player, so he’ll make adjustments throughout the game and he’ll figure it out."

There are two other players who could join Kirilloff to expand this exclusive club. Chas McCormick, the Astros' No. 24 prospect per MLB Pipeline, was included on Houston's roster for the series, while Shane McClanahan, the Rays' No. 6 prospect and the No. 99 prospect in MLB, was included on Tampa Bay's roster for its series vs. Toronto.

"Sometimes my emotions don't match up with my real reaction," Kirilloff said with a wry smile. "I was really surprised. Definitely happy and excited for the opportunity. We've stayed ready all summer. It’s really the same thing. If there is an opportunity and we're needed, our job is to stay ready and do our best."

Ranked the No. 27 prospect in baseball by MLB Pipeline, Kirilloff was the No. 15 overall selection in the 2016 MLB Draft out of the Pittsburgh area, and he hit .317/.365/.498 across four Minor League levels despite missing the entire 2017 season with Tommy John surgery. Widely considered one of the top pure hitting prospects in the Minors, Kirilloff topped out in 94 games with Double-A Pensacola last season, hitting .283/.343/.413 with nine homers and 18 doubles.

• What to expect from Alex Kirilloff in bigs

In addition to posting outlandish numbers at the plate in intrasquad games, Kirilloff worked at both corner-outfield positions and at first base during his stint at the alternate training site, and he could be an option at all three positions during the AL Wild Card Series as the Twins play matchups and weather the absence of Josh Donaldson and recent injury scares to Byron Buxton and Luis Arreaz.

"We have great faith in him," Baldelli said. "We wouldn’t be doing this if we didn’t think very highly of Alex Kirilloff’s ability both as a player and as a guy, as a person. He’s a very talented ballplayer. He’s got a tremendous offensive ceiling. He can really swing the bat. He’s got power to all fields.

"We’re obviously locked in on putting our lineup out there and putting our best folks out there right now, and we think our best lineup today has Alex Kirilloff in there."