Tiedemann (forearm) will undergo Tommy John surgery Tuesday, Keegan Matheson of MLB.com reports.
After seeking multiple opinions on his throwing arm, Tiedemann will ultimately undergo Tommy John surgery Tuesday, and he is expected to miss most or all of the 2025 season, per Matheson. The top pitching prospect for the Blue Jays, Tiedemann started four games for Triple-A Buffalo this season, posting a 6.00 ERA, 2.22 WHIP and 11:12 K:BB across nine innings.