The Orioles designated Zimmermann for assignment Thursday.
Zimmermann was pushed off the 40-man roster with the Orioles needing to clear a spot for infielder Emmanuel Rivera, who was claimed off waivers from the Marlins. The 29-year-old southpaw made 38 appearances (27 starts) with the Orioles over the previous four seasons, but even with injuries testing the big club's rotation depth in recent weeks, Zimmermann had yet to receive a call-up from Triple-A Norfolk in 2024. He's mostly served as a member of Norfolk's rotation when healthy this season, logging a 4.64 ERA, 1.47 WHIP and 60:25 K:BB across 66 innings.