Berkman experienced discomfort and swelling in his knee following Sunday's workout and underwent an MRI, which revealed a knee contusion. Berkman took ground balls and batting practice Wednesday and was held out of any running drills.
"It feels OK," Berkman said. "It's still a little swollen and a little sore, but the good news from the MRI is I'm not going to be able to hurt it worse. There's no reason not to try to do as much as I can with it. I told them I can run and would be more than happy to do as much running as they want me to do. Right now they're just trying to see how it responds to taking grounders and hitting and things like that."
Shortly after Berkman got the results of the MRI on Tuesday, he called Mills and tried to convince him to let him play Thursday against Washington. Mills said he wouldn't rule out Berkman making his spring debut as a designated hitter Friday against the Detroit Tigers in Lakeland.
"We are going to let it calm down, and if I can get him in the lineup a little bit on Friday, we will, but I will have to wait and see," Mills said. "I'm not opposed to waiting to see if we can get him in the lineup on Saturday. We might take two days, we might take one day. We'll see how he is after the workout today."
Berkman injured the knee while running the bases during Sunday's workouts and was taken for an MRI on Monday in Celebration. Houston team medical director Dr. David Lintner reviewed the MRI results on Tuesday and confirmed the original diagnosis of Dr. David Crumbie.
Berkman had minor surgery on his left knee in 1999 and underwent surgery following the 2004 season on his right knee to repair a torn anterior cruciate ligament. He said his left knee gave him some discomfort at different points in the winter.
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.