24-year-old, Casey Mize went to Springville High School in Springville, Alabama. He went 19–2 when he was in senior in high school. He was committed to playing collegiate baseball at Auburn University.
He pitched in 16 games with seven starts as a freshman in 2016, going 2–5 with a 3.52 earned run average (ERA) and 59 strikeouts. He played collegiate summer baseball with the Wareham Gatemen of the Cape Cod Baseball League after the 2016 season.
As a sophomore in 2017, Mize made 12 starts and went 8–2 with a 2.04 ERA, 109 strikeouts, and only nine walks in 13 games.
After the season, he spent the summer playing for the United States collegiate national team. For the 2018 season, Mize was named Auburn’s opening day starter.
Mize pitched the ninth no-hitter in school history against the Northeastern Huskies on March 9, 2018. Mize was 10-6 with a 3.30 ERA and 156 strikeouts in 17 starts in the season before.
Tigers manager A. J. Hinch said on March 26, 2021, that Mize will be in the starting rotation to begin the 2021 season. Mize got his first big league win on April 12th, as he pitched seven scoreless innings in the Tigers’ 6–2 win over the Houston Astros.
Mize made his major league debut as a hitter on August 24 against the St. Louis Cardinals, collecting an RBI on a bases-loaded walk. With five scoreless innings, he won the win.