WASHINGTON -- The Cardinals activated Lance Berkman from the disabled list on Saturday with the understanding that the veteran first baseman will be limited to a pinch-hit role for the immediate future.

Even Berkman described himself as merely "good enough" right now, an assessment that reaffirms his knee problems are not entirely behind him. During his nearly one-month stint on the DL, Berkman battled soreness in both of his knees. He underwent right knee surgery back in May.

Berkman pushed himself through six rehab games in Triple-A Memphis and finished 4-for-17 with three walks. His return does give the Cardinals a switch-hitting presence off the bench, though Berkman will likely have to be pinch-run for any time he reaches base.

"Right now I don't think we're in a position where we can start him," manager Mike Matheny said. "We're going to let the medical team continue to try and get him into a more stable spot."

Also joining the Cardinals from Memphis on Saturday was left-hander Sam Freeman, whose callup was sped up a few days because of the Cardinals' need for bullpen relief. St. Louis' bullpen had to cover 5 1/3 innings on Friday and has been summoned before the seventh in each of the team's last six games.

Freeman last pitched on Thursday, which was just his second outing back since dealing with a right oblique injury. That injury kept Freeman out for two weeks.

Prior to being sidelined, Freeman was terrific out of Memphis' bullpen. After pitching for St. Louis in June, Freeman returned to Memphis and limited opponents to three earned runs in 22 1/3 innings through Aug. 14.

"I was really confident in my fastball and attacking hitters," Freeman said. "My stuff was good, for the most part."

Freeman's arrival gives the Cardinals an eight-man bullpen and provides Matheny with a second left-handed reliever alongside Marc Rzepczynski.

Saturday marked the first day clubs are permitted to carry more than 25 players on their active rosters. As a result, the Cardinals did not have to make any corresponding roster moves to add Freeman and Berkman. The rest of the Cardinals' September callups are expected to join the team in St. Louis after the Minor League season ends on Monday.