Robert Guerrero will receive arthroscopic surgery Tuesday to repair a torn tendon in the rotator cuff of his left shoulder, the fighter told RingTV.com.

The decision was made after a 90-minute examination that included a second MRI by Dr. Michael Dillingham, who told Guerrero that he must refrain from even light exercise for four weeks and will be out of the ring for as long as six months.

Guerrero expressed optimism.

“The doctor said that I’ll be out for a good four weeks and then I’ll be able to do some light training and just shadowboxing and moving around,” said the 28-year-old Guerrero, a two-time IBF featherweight and one-time IBF junior lightweight beltholder,.

“I feel good. I feel good about everything. I’m just excited that everything is in motion and that I can get back into the ring and get back in there and to start training hard. That will get me ready to go full-force when I can later on.”

A team physician for the San Francisco 49ers, Dillingham advised Guerrero that he should “probably be out for four months in terms of punching and stuff based on what he’s seen,” said Guerrero’s manager Bob Santos.

“After the surgery, he would be in the sling for about two weeks and then he could shadow box, run, those kinds of things. He said we’re probably looking at four-to-six months” away from fighting competitively.

Guerrero had been preparing to face Marcos Maidana for what the WBA calls its “regular” title on Aug. 27 but had to pull out after he injured the shoulder throwing a punch during sparring.

Guerrero received an MRI on Saturday, which first revealed the tear. X-rays showed that there were no broken bones and that the injury was not career-threatening.

But Dillingham determined during an examination on Monday that a second MRI was needed.

“This time, they used a special dye that glows to see inside of another MRI, and it’s showing a partial tear in the rotator cuff. But Dr. Dillingham thinks that obviously because Robert makes his living as a professional prizefighter, that he should insure that there is nothing else going on in there,” said Santos.

“So [Dr. Dillingham] thinks that he should go in there on the side of caution to make sure, because sometimes things can go unseen whether or not you’re using the MRI or whether you do the dye that glows. So if there is something else going on, then he can co go ahead and fix that and take care of that partial tear.”

Guerrero was after his 14th consecutive victory and his 10th knockout during that run against Maidana (30-2, 27 KOs). Guerrero last suffered defeat by a split-decision to Gamaliel Diaz in December 2005 but won their rematch with a sixth-round knockout in June 2006.

Guerrero was is coming off of a one-sided, unanimous decision victory over Australia’s hard-punching Michael Katsidis (28-4, 23 KOs) in April, but has endured a tumultuous if not inspirational career

Guerrero chose in March of last year to pull out of a scheduled clash with Katsidis in order to be with wife Casey during her recovery from a bone marrow transplant.

Guerrero’s devotion to his wife and family were recognized when he received The Bill Crawford Award for Courage In The Face of Adversity from the Boxing Writers Association of America.

Assured that Casey’s cancer was in remission, Guerrero returned to the ring with an eighth-round knockout of Roberto David Arrieta in April of last year.

Guerrero’s comeback has included unanimous decisions over former four-time titleholder and Cuban Olympic gold medalist Joel Casamayor (38-5-1, 22 KOs) in July and a Vicente Escobedo (23-3, 14 KOs) in November.

After receiving his surgery, Guerrero believes that he will soon get back on track.

“I’m just excited to be able to get in with the specialist and to get it all done in a couple of days,” said Guerrero.

“So I’m just glad that it’s already getting under way and that I could get in so quickly. The doctor knows what he has to do to go in there and to take care of the problem.”

Lem Satterfield can be reached at [email protected]