In the fifth inning, Matsui fouled a pitch from St. Louis starter Todd Wellemeyer off the inside of his right knee and went down in pain, prompting team trainer Nate Lucero and manager Cecil Cooper to come out and check on the Astros second baseman. He stayed in the game and finished the at-bat -- striking out for the first out of the inning.
"He should be OK," manager Cecil Cooper said. "I'm sure he'll be a little bit sore."
Matsui laid down a sacrifice bunt in the Astros' five-run seventh inning. He was replaced by infielder Jeff Keppinger when Houston took the field in the eighth inning.
"It was good we were able to get him out after we got up and got a pretty good lead so he could go get some ice," Cooper said. "Hopefully he'll be OK for Wednesday."
Matsui had been nursing a sore left hamstring and before the game indicated that his hamstring was doing fine. He missed 18 games earlier this season because of a left hamstring strain.
Jason Grodsky is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.