Lance Berkman sidelined with sore knee

KISSIMMEE, Fla. -- Houston All-Star first baseman Lance Berkman is likely to miss the Astros' spring training opener Thursday after bruising his left knee.

The 34-year-old Berkman complained of soreness and swelling in his knee after Monday's workout. He had an MRI exam Monday night that revealed a contusion, and the results were sent to Houston to be further examined by team physician Dr. David Lintner.

The Astros should have a better idea of Berkman's prognosis in the next 24 to 48 hours, a team source told ESPN The Magazine's Buster Olney.

Manager Brad Mills said he'll probably keep Berkman out of Thursday's game against Washington.

"I'm not going to rule that out yet," Mills said Tuesday. "But I'm going to push back the decision. If I was leaning towards one way or another, it would be that he wouldn't be in the lineup."

Berkman's left knee has bothered him in the past. He had the knee scoped in 1999.

He said Tuesday that the knee started aching during the offseason, but he wasn't overly concerned heading into training camp. He thinks he tweaked the knee running bases during Sunday's workout.

"Obviously, it's concerning when your knee swells up the first time you're running the bases in spikes," Berkman said. "Whatever it is, it's minor, even in the worst-case scenario. I want to get out there as quickly as I can. I want to be on the field, out there with everybody, getting ready to go."

Berkman will sit out for the next few days and get treatment on the knee to decrease the swelling, the team said. He is officially listed as day-to-day.

Berkman missed 18 games in 2009 with a left calf strain and batted .274, a career low for a full season. The five-time All-Star is entering the final season of a six-year, $85 million contract extension which he signed in 2005.

-- Information from The Associated Press was used in this report.