The slugger has been dealing with a sprained right wrist since leaving a May 18 game against Houston after injuring it on a diving catch. He missed the next three games but returned to action May 22.
"It's been pretty sore since I've been back," Berkman said. "It got to the point where I could swing, it just never got better."
Berkman batted cleanup on Saturday, filling in for the injured Matt Holliday, going 1-for-5 with an RBI single and two strikeouts. Skip Schumaker took Berkman's spot in right field Sunday, with Jon Jay assuming the cleanup spot.
Manager Tony La Russa said the club scheduled Berkman's cortisone shot for after Saturday's game to allow the switch-hitter two days of rest before the Cards begin a nine-game road trip on Tuesday -- St. Louis has an off-day Monday. The Texas native has struggled against Cubs right-hander Carlos Zambrano, who started the game for Chicago on Sunday. Berkman has a career .155 average (11-for-71) against Zambrano, with four homers and 18 strikeouts.
Berkman is batting .329 and is tied for the team lead with 12 home runs. Since spraining his wrist, Berkman is hitting .268 (11-for-41) with one home run in 12 games. La Russa expects the outfielder to return to the lineup Tuesday in Houston.