"Since the All-Star Game, it's been good," Perez said. "No problem."
Manager Ned Yost just wanted to give Perez a night off.
"His leg does feel fine," Yost said. "We've got two days off in the next 50 games and I'm going to have to find spots to rest him."
George Kottaras made his 17th start behind the plate against the Orioles.
Dick Kaegel is a reporter for MLB.com. Kathleen Gier is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.