The move was made retroactive to Thursday.
Utility man Skip Schumaker was activated from the 15-day disabled list in time for Friday night's game at Pittsburgh. Schumaker played in four games during a rehab assignment with Triple-A Memphis and was 3 for 13 with two walks and two strikeouts.
Rookie Matt Carpenter is expected to get the bulk of the playing time and infielder Daniel Descalso played first base in the minors. Berkman has started seven games at first base, and Carpenter has started the other six.
Berkman said he took a bad step going after a popup, aggravating an injury that sidelined him last weekend. Rather than battle through the injury, the club felt it best that Berkman take enough time to recover.
Before the Cardinals played the Reds on Thursday, manager Mike Matheny said Berkman was day to day with no change in his condition from the previous night. But Berkman thought after Wednesday night's game that he'd need some time.
"It doesn't seem like it's going to be one of those that you can really push through," Berkman said. "It's certainly frustrating. I don't like missing time, I like being in there, being productive."
The 36-year-old Berkman was batting .348 with two RBIs in seven games. He was not in the lineup Thursday against the Reds.
"I certainly thought it was manageable and it wasn't prohibitive," Berkman said. "I took a bad step on that popup and it really kind of aggravated it pretty good."
Schumaker batted .283 last year in 367 at-bats with two homers and 38 RBIs as the primary second baseman. Before he was injured in spring training, the team had envisioned him as a super utilityman who could also start at all three outfield spots.