The first baseman accompanied the team to Cincinnati and had an intensified workout Friday before the opening game of a series against the Reds. The Cardinals planned to activate him a day later.
The 36-year-old first baseman tore cartilage in his right knee while stretching for a throw on May 19 and had surgery to clean it out. He didn't want to go on a rehabilitation assignment to the minors, preferring to ease back into an everyday role in the major leagues.
"There's really not a whole lot you can fine-tune until you get back in there and start playing against live competition," Berkman said. "For me, it's just making sure I get my body in shape to swing the bat. I don't expect to step back in there and be in midseason form."
Berkman has played only 13 games because of a pulled left calf and the knee injury. Allen Craig has started a team-high 28 games at first base, batting .313. Matt Carpenter has started 22 games at the spot and is batting .291.
Berkman said the depth at the position will give him a chance to return to a full-time role gradually.
"Because we have those guys, I can almost rehab at the big league level by playing a day, having a day off, playing a couple of days and having a day off, that kind of thing," Berkman said. "I don't have to be in there every day."
Manager Mike Matheny likes the idea of bringing Berkman back in Cincinnati. He has 23 homers at Great American Ball Park, the most by any visiting player.
Matheny acknowledged it will be a challenge to work him into the lineup.
"We're going to have to get creative; I don't think anybody has any doubts about that," Matheny said. "We're going to have to get guys rest. We're going to have to have some sort of rotation that's going to work out. It's a nice problem with everybody back."
Berkman was batting .333 when he got hurt.
"I felt great," he said. "My swing felt great. When I came back from the calf, it felt great. I know my swing pretty well. If I can get locked in like that, I generally end up with a pretty good year. I was definitely in a spot I was happy with. Now it's just a matter of trying to get it back to that spot."