"There's no pain and I feel good," Perez said. "Today, I feel like I can go on Friday."
Meanwhile, infielder Aaron Boone did some leg exercises and took batting practice in the cage Sunday. He said his left knee is "all right." Manager Manny Acta said Boone will be pinch-hitting for the next few days.
Boone said he felt pain in the knee when Washington played on the turf at the Metrodome in Minnesota.
"Structurally, I'm pretty sound. I'm not too concerned that it's anything serious," Boone said.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.