O'Day (right rotator cuff strain) said he was encouraged with how he felt on Wednesday, saying there was no pain. He also said that it's the best his arm has felt since hitting the disabled list.
Tillman's rotation return does not bump anyone from the O's rotation, at least not yet. Showalter said Ubaldo Jimenez, who took Tillman's spot, will pitch on Saturday in Detroit. Wade Miley will start Monday's game in Boston.
Brittany Ghiroli has covered the Orioles for MLB.com since 2010. Read her blog, Britt's Bird Watch, follow her on Facebook and Twitter @britt_ghiroli, and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.