Casey Mize will undergo Tommy John surgery, Detroit Tigers’ manager AJ Hinch announced Friday.
The procedure will repair the 25-year-old’s damaged UCL. According to MLB.com’s Jason Beck, the ligament is intact, but it was stretched to the point where it had lost elasticity. It ends the right-hander’s season. Mize is the second Tiger pitcher on staff to undergo the procedure in the last year, joining Spencer Turnbull, who went under the knife on July 31, 2021.
The news is disheartening, but not unexpected. The former first-overall pick has been on the injured list since April 14 when he was diagnosed with a right elbow strain. He was moved to the 60-day IL on June 1 and was eventually shut down from his throwing program on June 8 with continued elbow discomfort.
Mize started two games this season, going five innings in both appearances — a loss to the Chicago White Sox on April 9 and a win in Kansas City on April 14. He struck out just four batters and walked two in 10 innings, finishing the campaign with a 5.40 ERA.
This year was meant to be the one where Mize was fully stretched out and allowed to go as deep into games as he could. He was limited to four innings or fewer in each of his September 2021 starts to keep his innings down in an attempt to keep his elbow healthy. Despite that, he threw 150 1⁄3 innings with a 3.71 ERA and 116 ERA+. Were he to pitch a full season in 2022, such an inning limit would likely have been removed, allowing Mize to potentially pitch to his fullest potential.
Mize will miss the rest of this season and, most likely, most or all of 2023. At the latest, he should be back for Opening Day 2024. He’ll likely face a similar innings restriction to 2021 upon his return.