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03/21/12 1:35 PM ET

Carpenter likely to begin season on DL

Lohse to receive Opening Day start; Lynn moves into rotation

JUPITER, Fla. -- Chris Carpenter returned to St. Louis on Tuesday to undergo a new series of tests after weakness in his right shoulder and neck resurfaced during the right-hander's session of catch on Monday. This latest interruption of his spring throwing program leaves Carpenter set to begin the season on the disabled list.

Carpenter's spring routine was first stalled earlier this month by what he described as neck stiffness. An MRI suggested that the issue was being caused by a bulging disc in Carpenter's neck. After 11 days of rest and treatment, Carpenter resumed throwing on March 14. He threw off the mound once and faced batters in a live batting practice on Sunday. Everything felt fine during and immediately after the session.

However, when Carpenter went out to play catch the next day, his body didn't respond as he had anticipated.

"Things weren't just quite right," general manager John Mozeliak said. "I would use the term weakness. For precautionary reasons, we just think it's time to take a timeout, have him evaluated. We're trying to determine if it's the neck, the shoulder and what's causing the weakness. We don't know the answer to that yet."

Added manager Mike Matheny: "It just sets him up for further injury if he continues to push."

All the tests Carpenter underwent on Tuesday came back negative. He will undergo another series on Wednesday, with these focusing more on a potential nerve issue. Carpenter has had a history of nerve-related problems, and he chose to travel to St. Louis for this most recent round of tests in order to meet with the same doctors that have treated the issue in the past.

The Cardinals won't be able to establish a timeline for Carpenter's return or a blueprint for treatment until they know the root of Carpenter's discomfort. Mozeliak said that the club should have a pretty good idea of Carpenter's immediate future in about two days.

"They're just trying to go through the process to determine what that next step would look like," Mozeliak said. "It is something of a concern in the sense that it's reoccurring and we don't know the exact source. It may be related to that [bulging disc], but it looks like it could be something else."

Matheny, who just two days ago spoke about the possibility of Carpenter still making his Opening Day start, conceded on Wednesday that this latest setback will prevent Carpenter from beginning the year in the rotation.

   Chris Carpenter  /   P
Born: 04/27/75
Height: 6'6"
Weight: 230 lbs
Bats: R / Throws: R

"You could tell there was a little bit of hesitancy with him just not knowing how he was going to respond," Matheny said. "He wasn't feeling pain like he had been pushed too hard. It's just the next day his arm wouldn't respond. He's been fighting things for a long time -- different things. Mentally, physically, he's so tough. This is just another setback that he's going to answer the bell to. He always has."

With Carpenter out indefinitely, Lance Lynn will assume the fifth spot in the rotation. Lynn was recently put on a starter's routine in preparation for the possibility that Carpenter would not be ready.

Matheny also announced that Kyle Lohse will make the Opening Day start for the Cardinals, who had planned to give that nod to Carpenter. Adam Wainwright is still in line to start the club's home opener against the Cubs on April 13.

"The important thing now is to figure out what is wrong with Carp, get him back out there," Lohse said. "Last year, everybody pretty much discounted us after [Wainwright] went down. We had a lot of guys step up. It just shows what kind of character we have in here. Nobody feels sorry for us. If we start feeling sorry for ourselves, it's going to be a long year. We have a lot of capable guys who can step in there."

Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.