CHICAGO -- Mark Prior will have exploratory arthroscopic surgery Tuesday in hopes of determining what is wrong with the Cubs pitcher's troublesome right shoulder.

Dr. James Andrews will perform the surgery in Birmingham, Ala., Cubs general manager Jim Hendry said Monday.

"Hopefully, [Andrews] can go in there and find something that isn't major and hopefully help Mark's career get back on track," Hendry said.

Prior had pitched 10 1/3 innings this spring with the Cubs and was then optioned to Triple-A Iowa at the end of Spring Training. He was placed on Iowa's disabled list with right shoulder fatigue, and had stayed behind in Mesa, Ariz., at the Cubs' extended Spring Training camp.

Prior's only outing since Spring Training ended was two innings in Mesa on April 12, and that outing was cut short because of discomfort in his shoulder. He has been examined by orthopedic specialists Lewis Yocum and Andrews since then.

"Mark can find out once and for all if there's anything significantly wrong," Hendry said.

Prior had problems with his right shoulder in 2006 and was limited to nine starts before he was shut down. He hasn't been the same since a stellar 2003 season when he won 18 games and was named to the National League All-Star team.

The procedure Tuesday is supposed to be exploratory, but Andrews has clearance to make any repairs necessary if he can. Hendry said he talked to Prior this weekend.

"He was in good spirits," Hendry said of the 26-year-old pitcher. "I think he's at the point now where he realizes it's time for this to happen. You've got one of the best guys in the world doing it, and we'll find out [Tuesday]."

Prior has been on the disabled list at least once every year since he was called up in May 2002, but has never had surgery on his shoulder.

If Prior has surgery, does that mean he won't pitch in 2007?

"I have no idea," Hendry said. "We've been sending him to some of the best doctors in the world. It's gotten to the point where it's probably the right decision. Let one of the best people in the world go in there and have a look around."