Manny Pacquiao will undergo surgery on his right shoulder later this week in Los Angeles, his manager told The Times following the boxer's medical examination Monday.
“Manny and [his wife] Jinkee decided that in the best interest of his long-term health, he will have the surgery here this week,” Michael Koncz said.
Koncz said Pacquiao (57-6-2), a record eight-division world champion, is expected to be sidelined four to six months.
Pacquiao, defeated by unanimous decision Saturday night in his long-awaited bout against Floyd Mayweather Jr. at MGM Grand in Las Vegas, “exacerbated” the shoulder he first hurt in an April 4 sparring session, Koncz said.
When examined last month, a tear was found below the rotator cuff, and Pacquiao said Sunday it felt like the damage increased when he subjected Mayweather to effective combinations in the fourth round of their fight.
Monday's examination confirmed what was expected.
“He's got to do [the surgery],” Pacquiao promoter Bob Arum said. “He hurt it after the [2008 Oscar] De La Hoya fight [in a Jet Ski mishap], and it got better.”
Despite the pain after the sparring accident, Pacquiao opted to fight Mayweather after resting the shoulder and believing he could take an anti-inflammatory shot of Toradol before the bout.
The Nevada State Athletic Commission, however, rejected that request in the hours before the bout, explaining that among other miscommunication, Pacquiao checked “no” Friday to a medical form question asking whether he'd experienced a shoulder injury.
The medical form was completed and signed under penalty of perjury, and commission Chairman Francisco Aguilar said he has asked the state's attorney general to determine what that means in light of the events with Pacquiao's injury and the magnitude of the bout that is expected to shatter all revenue records.
“The real question is why ‘no' was checked,” said Travis Tygart, head of the U.S. Anti Doping Agency, which had written to Pacquiao's camp last week that Toradol was an acceptable in-competition medication.
Arum didn't have an answer to Tygart's question.
“That, I can't explain,” he said. “The whole system, of dealing with this eminent association and also the commission, with its own rules, doesn't work. We put on the form what medication he was taking. Why not ask us why he's using that medication?”
Pacquiao and his promoter issued a joint statement trying to clarify why they proceeded from the April 4 injury without seeking a postponement.
“His advisors concluded that with short rest, treatments and close monitoring, Manny could train and, on May 2, step into the ring against Floyd Mayweather Jr.
“Manny continued to train and his shoulder improved, though not to 100%,” the statement read. “This is boxing, injuries happen, and Manny is a warrior.”
Aguilar told The Times on Monday that he was never told of the treatment plans — by USADA or the Pacquiao camp.
So when Pacquiao's team, with two doctors in his dressing room, prepared for the injection, the commission stopped it.
Aguilar said he not only lacked proof that Pacquiao was injured, he was uncomfortable sending an injured fighter into the ring with a medication that would mask the pain and perhaps lead to a worse injury. Aguilar said he even ordered Pacquiao to throw punches with his right hand in warmups.
If Pacquiao had shown too much pain, Aguilar said, he was empowered to postpone the fight on the spot.
Instead, the bout proceeded, and Mayweather, 38, out-punched Pacquiao, masterfully evading the Filipino's typical aggression and avoiding the southpaw's best power punch.
“Following surgery, we will have a fuller assessment of the situation,” Koncz said.
Follow Lance Pugmire on Twitter @latimespugmire