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09/10/12 10:40 PM ET

Lynn to step in for Westbrook vs. Dodgers

SAN DIEGO -- When Cardinals starter Jake Westbrook injured his right oblique muscle in his last start, a spot opened up in the St. Louis rotation, and a crucial spot at that: Westbrook's next scheduled start would have come Thursday in Los Angeles against the Dodgers, who are in hot pursuit of the Wild Card spot the Cardinals currently hold.

Given the importance of the game, manager Mike Matheny and the Cardinals brass announced Monday that righty Lance Lynn will fill in for Westbrook, due in large part to the fact that he is the most proven and experienced option available.

Lynn was chosen over 22-year-old rookie Shelby Miller, who made his big league debut last Wednesday, and Trevor Rosenthal, who made his on July 18. Both are currently in the Cardinals' bullpen and would have been able to provide length Thursday, if called upon.

"A lot of thought went into it," said Matheny. "Being in L.A., being against L.A., being where we are right now, it's a lot to throw on a young player. Lance has been a pitcher that's pitched in as high-leverage situations as anyone. We know that's not going to affect him, and we believe in his stuff."

Lynn, who tossed a scoreless inning of relief Sunday, was in the midst of a highly impressive rookie season (14-7 in 25 starts overall and an All-Star bid), before he was derailed by some August struggles that led Matheny to remove him from the rotation on Aug. 24. But the 25-year-old pitched in 10 games during St. Louis' World Series run last season, and has shown he can pitch in high-pressure situations.

"Lynn obviously deserves an opportunity again," said general manager John Mozeliak.

He may only need to make one start, as the Cardinals received good news regarding Westbrook on Monday. His oblique injury is localized and "as good as it could possibly be," according to Matheny, who added that the team expects Westbrook back this season. When that might be remains unclear.

Berkman to have surgery, season is over

SAN DIEGO -- A frustrating, injury-riddled year for Lance Berkman has officially come to an end as of Monday. Berkman flew home to Houston to have his troublesome right knee examined, and it was determined that the 36-year-old veteran will require meniscus surgery, a procedure very similar to the one he had in May, scheduled for Tuesday in Houston.

Berkman has battled to recover from that May surgery, a comeback slowed when he was hit by a pitch on July 24.

He has been rehabbing since, and was recalled to the Cardinals on Sept. 1, feeling good enough only for limited pinch-hit duties.

Berkman met with general manager John Mozeliak, manager Mike Matheny and trainer Greg Hauck and "the consensus was at this point in the season and with the diminished role I was playing, it just wasn't happening," he said.

In the midst of the frustrating up-and-down comeback attempts, Berkman indicated that 2012 might be his final season. He's made just six plate appearances since Aug. 3 and played in just 31 games all season. But he says he's not making any decisions just yet.

"I'm leaving my options open," Berkman said on Monday.

As disappointed as Matheny was to lose the production of a man who was once a lock for 25-plus homers a year, he said the toughest part of watching Berkman's 2012 saga was the toll he knew it took on Berkman.

"It's tough on a player who's just been beat up, fighting all season ... just the mental anguish of: Can I do this, now what, what's next, all the hype, then the disappointment. It's just an absolute roller-coaster," Matheny said.

"I felt like I've pretty much exhausted all other avenues," Berkman said. "I did the strengthening program, two injections, one in each knee. There were things we tried. It wasn't happening. Unfortunately, this is the last resort. I gave it a go."

Carp tests arm as he holds out hope of returning

SAN DIEGO -- Cardinals right-hander Chris Carpenter threw 70 pitches in a simulated game before Monday's game at Petco Park. It was another step in the right direction for the former Cy Young winner, who underwent thoracic outlet surgery in July.

"Everything's good," Carpenter said. "My stuff today was sharp, my cutter was sharp, I threw my breaking ball for strikes, my fastball on both sides of the plate, which was good."

Carpenter and the Cardinals have tried to temper any hype surrounding a potential late-season return, though the 37-year-old is scheduled for one more simulated game, a 90-pitch outing set for Saturday, which would likely be his last before a potential start.

According to both Carpenter and his manager, Mike Matheny, the stuff he showed in the simulated game was good enough to take into a real start. But Matheny has not gone so far as to project a return date yet.

The concern is obviously that Carpenter would rush back, re-injure himself and diminish his availability for the 2013 season, which was, after all, the expected return date all along. Still, Carpenter's effort Monday seems a reason for optimism.

"It was a very good outing today. Had more life on the ball, crisp movement, and he held it all the way through, right until his last pitch, the same stuff," Matheny said. "So it was all very encouraging."

Worth noting

• In the wake of the news about the end of Lance Berkman's season, the Cardinals recalled catcher/first baseman Steven Hill prior to Monday's game. The addition will bolster the team's right-handed power options off the bench.

Hill hit .266 in 87 games with Triple-A Memphis and was at home with his family in Houston when he got the call. Memphis's season has been over for a week.

"I didn't expect anything," Hill said. "I was sitting at home, just enjoying the family, hanging out. When you're in Triple-A, you keep an eye on what they're doing just to see what would happen. I've been kind of in the loop with [the Cardinals' season]. It's exciting."

• Double-A Springfield outfielder Chris Swauger had successful surgery to repair his broken collarbone Monday, a day after he injured it in a 3-1 playoff win over Tulsa. Swauger will be unavailable for Springfield as it takes on Frisco in the best-of-five championship series.

Chelsea Janes is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.