Baumann was optioned to Triple-A Norfolk on Monday.
Baumann was recently recalled by the Orioles, and he allowed a run on three hits and no walks while striking out two in 3.2 relief innings against the Rays on Saturday. He's posted a 4.91 ERA and 1.45 WHIP in 11 innings over six outings with the major-league club this year, but he'll head back to Norfolk after Marcos Diplan was recalled Monday.