JUPITER, Fla. -- The waiting continues with regard to Cardinals co-ace Chris Carpenter.

For the third straight day Thursday, Carpenter was being examined by nerve specialists in St. Louis to determine the cause of what has been described as "weakness" in his neck, shoulder and upper arm and decide on the best course of action.

There wasn't much of an update on Carpenter's situation before Thursday's game against the Nationals.

"We really don't know anything," manager Mike Matheny said. "He has more tests today. The things he's been tested on already, there haven't been any real [red] flags. When we get the results all together, then we'll be able to give you guys more."

A more substantive update is expected Friday.

Carpenter has already been ruled highly doubtful to be ready to break camp for Opening Day. The question is how deep into the season the Cards can expect to be without Carpenter. He has been bothered by a bulging disc that affected a nerve in his neck, and though he threw a successful batting practice session Sunday, he felt discomfort the following day and returned to St. Louis.

His condition has been compared to the nerve-related issues that prematurely ended his seasons in 2004 and '08 and also bothered him in 2010.

Beltran likely to see time in center vs. lefties

JUPITER, Fla. -- With Allen Craig progressing well in his return from right knee surgery, Mike Matheny expanded his look at lineup possibilities for the Cardinals on Thursday by giving Carlos Beltran his first start in center field. Left-hander Gio Gonzalez was on the mound for the Nationals.

Because of past knee woes, Beltran hasn't played center field in the regular season since 2010. But the Cards are counting on Beltran making a smooth transition to center on certain days a left-handed starter is on the mound, because that would allow the right-handed-hitting Craig to start in right field.

While Craig might also spell Lance Berkman at first from time to time, the key to his getting consistent at-bats will be Beltran shifting to center in place of Jon Jay.

"I think that would be the easy thing," Matheny said. "Right now, Jon Jay plays an extremely good center field. We know that we can preserve Carlos a little bit more by putting him in right, where there's not as much demand [on his body]. But we also understand we want to get Allen some at-bats. So we'll have to be creative at times, and there are other times where it will work itself out. It will probably be a better fit for Carlos to be in center than for Allen, so when we do have a left-handed pitcher, it makes sense to give Carlos some repetition to where he feels comfortable out there. He's had more innings there than anywhere else, so he should feel comfortable."

Matheny said he has been impressed with the way Beltran has paced himself this spring, and it's clear the veteran Beltran understands the intricacies of outfield play.

"You can tell he thrives on doing things right," Matheny said. "And that's what center field is -- the conscientiousness."

To that point, Matheny and his staff have been pleased with the strides Jay has made in "quarterbacking" in the outfield.

"He's not afraid to say something to Matt Holliday or Carlos," Matheny said. "That's what center field is about. Watching infield play, watching the positioning, watching the particular at-bat."

The Cardinals still haven't ruled out the possibility of Craig, who is appearing in Minor League games, being ready by Opening Day.

Cards set pitching rotation for start of season

JUPITER, Fla. -- With Chris Carpenter ruled out of the mix for Opening Day, Mike Matheny has set his rotation for the start of the season.

As announced Wednesday, Kyle Lohse will start the season opener in Miami, and Adam Wainwright will get the nod in the home opener at Busch Stadium on April 13. The rotation, in order, from the start of the season will be Lohse, Jaime Garcia, Wainwright, Lance Lynn and Jake Westbrook. Westbrook will have an extra day of rest between his last spring outing and his first regular-season start on April 9 in Cincinnati.

"It will be a little funny with Jake, it looks like," Matheny said. "But then we'll fall into the rotation as it's looked in Spring Training."

Worth noting

• In addition to trying Carlos Beltran out in center field, manager Mike Matheny is also getting a look at him in the two-hole. That's where Beltran hit Thursday. Matheny believes there's a good argument for getting Beltran as many at-bats as possible within a game. "We've got the ability to put Carlos in those three, four or five spots, but he also fills that two-hole pretty nice. He can be in any of those and fit in extremely well. Right now, the way everybody else is going, it just makes sense to put him there."

• The Nationals' lineup that Jaime Garcia faced Thursday at Roger Dean Stadium can best be described as a "B" group, but give Garcia credit, nonetheless, for a strong outing. He went five innings, allowing just three hits while striking out nine. "I was really excited to get this one out of the way, going five innings," Garcia said. "Basically just getting a good feeling with my mechanics and my pitches ... getting a good feeling and getting my rhythm. I was able to keep the ball down. That's basically what I want to do every time I go out there -- make my pitches and keep the ball down."

• One of the greatest switch-hitters in history, Chipper Jones, announced Thursday that he will be retiring at season's end, and another great switch-hitter, Lance Berkman, shared some thoughts on that. "It's amazing," Berkman said. "You look at the switch-hitters in the history of the game, and very few ... I think there's two with more home runs [Mickey Mantle and Eddie Murray], maybe one with more RBIs [Murray]. It's amazing when you think over the 120-year history of the game that he's in such elite company. Another thing that's pretty remarkable is that he stayed in Atlanta his whole career. That's a real special thing that you don't see often. He's a legend there."