PITTSBURGH -- Xavier Nady left Tuesday's ballgame against the St. Louis Cardinals in the fourth with a strained left hamstring. Nady singled to open the inning but then bent over in obvious discomfort while trotting back to first after Ryan Doumit lined a ball foul.

"He felt something with that hamstring," manager Jim Tracy said. "With the conversation that we had and with what I heard, it just didn't seem like it would be a very wise thing to watch this guy run from first to third if there is a hit."

Nady will likely not be in the lineup on Wednesday, though the outfielder said that he does not expect to be out of action for more than a few days.

"It wasn't a pop," Nady said, "but I felt something."

That "something" was enough to take the precautionary measure of taking Nady out of the game early, especially considering Nady's left hamstring has been a lingering bother throughout the season.

The right-fielder missed nearly two weeks of playing time early in the season after leaving an April 21 game with a strained hamstring. Then on June 6, Nady aggravated that hamstring again and was forced out of the Pirates' game against Washington prematurely. He didn't return to the outfield until June 12.