Guardians outfielder Chase DeLauter did something in 2025 that only five Major Leaguers had done before him.
Cleveland's No. 2 prospect hadn't appeared in a regular-season game prior to that year's playoffs, but after making the Guardians' 26-man roster for their American League Wild Card Series versus the Tigers, DeLauter was Cleveland's starting center fielder in Game 2. That made him just the sixth player to enjoy a Major League debut on the postseason stage.
Here are all the players who have made their MLB debut in the playoffs, starting with the most recent. It's worth noting that three of these examples occurred in 2020, when there was no Minor League season and only a 60-game regular season schedule due to the COVID-19 pandemic.
Chase DeLauter, Guardians -- Oct. 1, 2025
A 2022 first-round Draft pick, DeLauter hit a bump in the road almost immediately in his MLB debut as he committed a fielding error in his first inning in the Guardians' outfield. But his big day improved from there. DeLauter walked in his first plate appearance, hit a ball at 110.8 mph (for a lineout) and provided a critical outfield assist during Cleveland's 6-1 victory in Game 2 of its AL Wild Card Series versus the Tigers.
Ryan Weathers, Padres -- Oct. 6, 2020
Weathers, the No. 7 overall Draft pick by the Padres in 2017, made his big league debut in Game 1 of the 2020 National League Division Series against the rival Dodgers. Brought in to face Los Angeles' big lefty bats, Weathers got Corey Seager to line out, Max Muncy to fly out and struck out Cody Bellinger in 1 1/3 scoreless innings of relief.
Shane McClanahan, Rays -- Oct. 5, 2020
A year before he was the Rays' Game 1 starter for the 2021 American League Division Series at age 24, McClanahan was a Top 100 prospect taking the mound for the first time against the Yankees in Game 1 of the 2020 ALDS. The hard-throwing lefty made four relief appearances in the playoffs and struggled at times, but his best one came in the World Series against the Dodgers, when he pitched a scoreless ninth inning in the Rays' Game 3 loss.
Alex Kirilloff, Twins -- Sept. 30, 2020
Kirilloff was ranked the No. 27 overall prospect in baseball when the Twins added him to their Wild Card Series roster for the 2020 postseason. The 22-year-old lefty slugger drew the start in right field for Game 2 against the Astros and went 1-for-4 with a single. He lined out with the bases loaded in his first career at-bat but ripped a base hit in the next one and made a terrific sliding catch in right field.
Adalberto Mondesi, Royals -- Oct. 30, 2015
The Royals shortstop became the first player to make his Major League debut in the World Series, pinch-hitting for Kansas City in the fifth inning of Game 3 against the Mets at Citi Field. The 20-year-old speedster struck out against Noah Syndergaard in his only at-bat.
Mark Kiger, A's -- Oct. 13, 2006
Kiger is unique because he only played in the postseason. The second baseman never played a regular-season game in his career. His two appearances in the 2006 American League Championship Series against the Tigers were his only Major League games -- and he never even got a plate appearance, playing only as a late-game defensive replacement. His debut came when he subbed in at second in the eighth inning of Game 3, and he did the same in the ninth inning of Game 4.