CHICAGO -- Cubs infielder Ryan Freel had to leave Wednesday's game because of a strained left hamstring, and he may be headed to the disabled list.

Freel, who made his fifth start at third base against the Pittsburgh Pirates, injured himself when he slid after rounding first base in the fourth inning. He had singled with one out and was headed to second but slid hard in the dirt to stop and scamper back to first.

The Cubs expect to know more about Freel's status on Thursday. If the injury does require him to go on the disabled list, the Cubs may call infielder Bobby Scales back. Scales was sent down to Triple-A Iowa on Wednesday because the team wanted someone who could back up at shortstop and had recalled Andres Blanco.

On Wednesday, infielder Aaron Miles was placed on the 15-day disabled list with a strained shoulder. Third baseman Aramis Ramirez (shoulder) and pitcher Rich Harden (back) also are on the DL.

"If Scales isn't too far, he should catch a taxi back from the airport," Cubs manager Lou Piniella said after Wednesday's game.