Left-hander Zac Lowther, who struck out 10 in six shutout innings Wednesday for Low-A Delmarva, was promoted Monday to High-A Frederick. He had a 1.16 ERA in six starts. ... Showalter said reliever Darren O'Day, who is on the disabled list with a hyperextended elbow that required a cortisone shot this weekend, might throw Tuesday. ... Colby Ramsus' hip is still "nagging," Showalter said, and the outfielder hasn't begun to play in extended spring training games. ... Closer Zach Britton, who will begin his rehabilitation assignment with Triple-A Norfolk on Wednesday, is excited, Showalter said.