CHICAGO -- Carlos Zambrano may want to work on his sliding technique.

The Chicago Cubs pitcher had to leave Saturday's game against the Boston Red Sox after five innings because of a sprained left big toe injured when he slid into second base in the fifth inning. Precautionary X-rays were negative, Cubs athletic trainer Mark O'Neal said, and Zambrano was not expected to miss a start.

Zambrano had singled to lead off the fifth and was forced out at second on Neifi Perez's grounder.

"It was an ugly slide," Cubs manager Dusty Baker said. "I was hoping he could give us another inning, but he couldn't push off with that toe."

Zambrano received treatment in the dugout after the slide, and took the mound for the sixth. But after a warmup pitch, he signaled to the bench to take him out.

"When he flexed over, he had trouble getting over his landing foot, because he didn't want it to bend backwards and he said he couldn't go with it," O'Neal said.

O'Neal is calling the injury a "turf toe."

"I'm not anticipating it to be long term," O'Neal said. "His nail bed was a little tender, but that's to be expected. When he left, he was walking a little better. It's day to day. We don't anticipate him missing a start."

The right-hander had given up four runs on five hits and three walks over five innings while striking out eight. When he left, the game was tied, 4-4, and the Cubs went on to beat the Red Sox, 7-6.