The outfielder hasn't played since last Saturday and could return this weekend. So far there hasn't been any serious discussion to place him on the disabled list.
"He has to be able to do some baseball activity," manager Ron Roenicke said. "We feel like whether it's Saturday or Sunday, we'll get him back in."
Meanwhile, Matt Garza, who left his start in St. Louis on Wednesday with a bruised right thumb, is also making progress.
"The trainers are happy," Roenicke said. "He's still black and blue, but the swelling's gone down. I don't know if it's gone completely."
Garza will be further evaluated during a side session Friday.
"We think everything's going to be fine," Roenicke said. "If he goes out there and says he can't do it, we'll have to change our plan."
Alyson Footer is a national correspondent for MLB.com. Follow her on Twitter @alysonfooter. Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. This story was not subject to the approval of Major League Baseball or its clubs.