HOUSTON -- The Rangers could be without both Josh Hamilton and Milton Bradley for Wednesday's game against the Astros at Minute Maid Park.

Hamilton had to leave Tuesday's game after two at-bats and four innings on defense with inflammation in his left knee.

The initial report out of the Rangers clubhouse was there was no structural damage. He'll be re-evaluated on Wednesday and is officially listed as day-to-day.

"I'm all right," Hamilton said. "Obviously, you go through a season having aches and pains, but we want to get it better before it gets bad."

Hamilton said he first hurt the knee last Thursday against the Braves when he made a diving catch on a ball hit by Chipper Jones in the first inning. He said he has felt it off-and-on since then. He said he has been getting treatment when it was sore and none when it felt fine.

He showed up for early batting practice on Tuesday and said the knee felt fine. It continued to stay that way through batting practice before it started barking at him when he stepped out of the dugout for his first at-bat in the first inning. He hit a ground ball to first baseman Lance Berkman, who turned it into an inning-ending double play.

"Obviously it was hurting, because I couldn't beat out that double-play ball," Hamilton said.

Hamilton was also unable to make a diving catch on a soft line drive hit by Ty Wigginton in the fourth inning. He came out of the game after that inning.

This is the same knee on which Hamilton had surgery during Spring Training in 2006 and again in July of that year.

"You are always concerned when one of your big boppers goes out of the lineup," Rangers manager Ron Washington said. "At least there was no structural damage. That's a good thing."

Bradley was out of the lineup for the sixth straight game with a strained quad muscle. He pinch-hit in the seventh inning and lined out. Bradley tested the muscle before the game and told Washington he was "80 percent."

Washington decided that wasn't worth the risk and held Bradley out. Both he and Hamilton may not play on Wednesday.

"Somebody else will have to step up," Washington said. "The game has to be played, so we'll put nine guys out there."