Cardinals' Berkman headed to DL

St. Louis Cardinals first baseman Lance Berkman is headed to the 15-day disabled list after he aggravated a left calf injury chasing a popup.

General manager John Mozeliak told reporters that the team would activate Skip Schumaker from the DL for Friday's game at Pittsburgh. Schumaker had been on a rehab assignment with Triple-A Memphis.

Berkman told reporters that he took a wrong step pursuing a popup. Rather than fight through the discomfort, the team wants to give Berkman ample time to get healthy.

"It doesn't seem like it's going to be one of those that you can really push through," Berkman said after Wednesday's game. "It's certainly frustrating. I don't like missing time, I like being in there, being productive."

Berkman, 36, was batting .348 with two RBIs in seven games. He wasn't in Thursday's lineup against the Reds.