Manny Pacquiao will undergo surgery on a shoulder injury this week and could be out of action for up to a year following his unanimous points defeat by Floyd Mayweather, according to reports in the United States.
Pacquiao could also face a possible fine or suspension after answering 'no' on a Nevada Athletic Commission (NAC) questionnaire ahead of the welterweight unification showdown in Las Vegas last Saturday.
He did not submit any injuries before the fight, but cited a shoulder problem after it.
''We were planning to postpone because for two weeks I didn't train well. We couldn't do what we wanted to because of my shoulder,'' Pacquiao said after the bout.
''From the third round I felt the pain in my shoulder. When I threw a lot of punches it hurt, so I backed off."
He could now be set to spend time out of the ring while he recovers.
Orthopedic surgeon Dr Neal ElAttrache told ESPN.com that 36-year-old Pacquiao will have surgery to fix a "significant tear" in his rotator cuff this week which looks set to enforce a nine- to 12-month absence from the ring.
ESPN added that the surgeon is understood to have examined Pacquiao in Los Angeles on Monday.