Zimmermann was recalled from Triple-A Norfolk on Saturday.
Zimmermann made two starts while with the Tides, including a shutout versus Worcester on June 13. He allowed three runs, 14 hits and three walks while striking out 11 innings across 15 innings during his most recent stint in the minors. For now, it appears he'll be a fresh bullpen arm for the Orioles. He has a 7.20 ERA and 6:0 K:BB over five innings across two major-league appearances. Logan Gillaspie was optioned out in a corresponding move.