ST. LOUIS -- Due to a conflict with the schedule of his surgeon, Lance Berkman will undergo right knee surgery on Friday, a day later than initially planned.

Berkman will have the procedure done near his home in Houston. In addition to repairing the torn meniscus in Berkman's right knee, the surgeon will determine if the first baseman's anterior cruciate ligament has also been compromised or torn. If surgery is needed on the ACL, Berkman will not return in 2012.

Though a magnetic resonance imaging exam did not detect any ACL damage, Berkman has said that he expects to find the ligament compromised based on the instability he had been feeling.

Berkman has been away from the team since Tuesday.

"I've been preaching all year to control the things we can control, and we certainly can't control what they're going to find when they go in there and start doing some exploration," manager Mike Matheny said. "But obviously I've been thinking about him, praying for him. I want the best to happen for him, as much for us."

Mental approach work in progress for Freese

ST. LOUIS -- Given no choice by his manager, David Freese spent Monday and Tuesday away from the field, clearing his head and working to fix his swing.

He returned with a 2-for-4 night, including his ninth homer, in Wednesday's 6-3 win over the Padres and he went 2-for-5 with his 10th home run in Thursday's 10-9 loss to the Phillies.

But getting out of this funk is not the only learning curve Freese has endured. The battle he's continuing to fight is the one within himself.

"I think I handle the highs pretty well, but when things go down, I'm hard on myself, and I think everybody knows that," Freese said. "I'm my biggest critic. I think that's something I obviously need to work on, but I expect the best out of myself. When you expect perfection, you're going to be fighting it."

Manager Mike Matheny noted that, results aside, his third baseman "just looked like himself" on Wednesday. That's a good sign, as Freese wasn't out to overhaul his swing mechanics, but to get them back to where they were when things were going well.

Freese entered Wednesday having hit safely in only one of his previous nine starts. His batting average dipped from .312 to .259 during that span. He was asked after his two-RBI game on Wednesday how he went about clearing his mind during the time off.

"Take a breath first," Freese answered. "You understand that you can't make this game harder. You just try to simplify everything, slow everything down at the plate. Just doing what you need to do and not be superman out there."

Craig moving forward with hamstring rehab

St. LOUIS -- Allen Craig (left hamstring strain) took another step forward in his recovery by joining teammates for batting practice and fielding work on Thursday. He also tested his hamstring by running for a second straight day.

"It felt fine," Craig said afterward. "I'm progressing well. I'm feeling pretty good."

The injured first baseman/outfielder was cleared to take swings off a tee on Wednesday, and Thursday marked the first time he had hit on the field since exiting the team's May 16 game in San Francisco.

Craig is eligible to come off the 15-day disabled list as early as June 1, and he is hopeful that he will do so on that date. He has not yet been told whether the team will send him out on a brief Minor League rehabilitation assignment before removing him from the DL.

Craig appeared in 13 games in between DL stints. He began the year sidelined after offseason surgery on his right knee.

Worth noting

• Lefty reliever J.C. Romero, who was recently released by the Cardinals, has signed a Minor League deal with the Orioles. In eight innings with St. Louis, Romero allowed nine earned runs on 14 hits.

• This four-game series between the Cardinals and Phillies marks the first meeting between these clubs since last year's National League Division Series. The Cardinals won that series in a decisive fifth game, despite the Phillies entering as the heavy favorite.

"It's definitely something I'll never forget," Skip Schumaker said of that series. "It was quite an experience."

• In an effort to make their home run celebrations more efficient, the Cardinals have recently developed a home run receiving line in the dugout. The system, which Schumaker guessed was first suggested and coordinated by Berkman, begins by having everyone in the dugout line up along the back. The batter who just homered then runs down the line giving a string of high fives.

"I think because there are so many guys in the dugout and everyone is sick and tired of going through this whole 55 different handshakes," Schumaker said. "It's quicker, and it ends up being kind of funny, too."

Matheny said he remembers seeing a similar procession in Japanese games.

"I admire their individuality, I guess," Matheny said. "I'm sure there's going to be Little Leaguers all over the country doing that."

• After committing 10 errors from May 13-19, the Cardinals did not commit any while sweeping the Padres to begin this homestand. It was the first errorless series St. Louis had played since May 6-8, when it swept Arizona.