KISSIMMEE, Fla. -- Two key members of the Astros' roster may be out of commission for the next few days after suffering injuries during recent morning workouts.

Lance Berkman strained an oblique muscle on his left side while hitting left-handed during the first full-squad workout. Brandon Backe will likely be sidelined for a couple of days after he was hit on the right foot by a Carlos Lee batted ball while throwing batting practice on Saturday.

X-rays on Backe's foot, taken early Sunday morning by team doctor Tom Mehlhoff, were negative, and the club is categorizing the injury as a bone bruise. The right-hander will not pitch the Grapefruit League opener on Thursday as planned. That start will likely go to left-hander Mark McLemore, who was originally scheduled to pitch after Backe on Thursday.

Backe, who was walking on crutches as he left the Spring Training complex, pitched behind a protective screen while throwing batting practice, but he left himself partially exposed and vulnerable to line drives back to the mound.

"I don't like to pitch with the screen there, anyway," he said. "I move it out of the way just enough. ... I have protection still, but not full protection. It missed the screen and got what part was still showing, which is my foot.

"This is just a freak, innocent injury. Thank gosh it's not as bad as it feels. No fracture, no break. It just hurts. ... I can't walk on it. The only thing it's going to keep me from doing is exercise and throwing."

Backe is confident this setback will keep him out of action for only one game.

"I'm not going to miss much," he said. "It's one of these things that happens. I can tell you now, I'll learn to pitch over the screen instead of trying to do what I've been normally doing."

Berkman's injury could sideline him him for a while. He'll definitely sit out Monday's intrasquad game, and he will not travel to Winter Haven with the club on Thursday.

"That might be a little more than we anticipated, too," manager Cecil Cooper said. "It's Lance Berkman, and I'd rather it be now than a month from now. When you're talking about the rib cage, that could be an issue for a long time."

Although Berkman spent some time swinging in the cages this offseason, he suspects his recent setback may be partially due to a long stretch of relative inactivity during the offseason, as compared to the every day routine during the season.

And he's not overly concerned with the idea of not being ready to play the Grapefruit home opener this weekend.

"You don't want to do anything to really hurt yourself," he said. "Who cares about playing the first two weeks of Spring Training? It's one of those deals, I want to try to be ready for the [regular season] opener. I don't care about being ready for the Spring Training opener."

Berkman joked that he's somewhat pleased that he can use the injury excuse in order to get out of working too hard this spring.

"Hopefully, I can milk it for at least another week and a half," he quipped. "Hopefully, I can use it for an excuse for underperformance. I was a little disappointed last year, not the fact that I hit .278, but that I couldn't come up with an injury to justify it."

Bonding: Carrying on a yearly tradition, Brad Ausmus treated the catchers, plus select members of the coaching and athletic training staffs, for dinner Saturday night.

Ausmus was reluctant to talk about the evening, saying only that the reason behind the gathering was "comaraderie."

The Astros have six catchers in camp this year: Ausmus, J.R. Towles and Humberto Quintero, plus non-roster invitees Alberto Castillo, Josh Johnson and J.R. House.

Intrasquad: Berkman will not be the only starting position player to not participate in Monday's intrasquad game. Miguel Tejada, Lee and Ausmus probably won't play either, but they are slated to play on Tuesday. The group of veterans also will not make the trip to Winter Haven on Thursday, but will play in the home opener Friday.

"We'll give the veterans off one day," Cooper said. "Let the other guys get some swings in. They probably won't play the first spring game anyway, so they'll get some extra work on the backfields."