As previously reported, Manny Pacquiao could face disciplinary action from the Nevada State Athletic Commission for failing to disclose a shoulder injury prior to his twelve round decision loss to Floyd Mayweather Jr. this past Saturday night at the MGM Grand in Las Vegas.

According to Fox Sports, Nevada Athletic Commission chairman Francisco Aguilar said Monday that the state attorney general's office will investigate as to why Pacquiao checked "no" a day before the fight on a commission questionnaire asking if he had a shoulder injury.

Pacquiao could face a possible fine or suspension for not answering the question accurately on a form he filled out prior to last Friday's official weigh-in.

Following Pacquiao's loss to Mayweather, the boxer and his promoter Bob Arum of Top Rank revealed that Manny had suffered a right shoulder injury several weeks ago in training camp. An MRI was taken weeks ago and revealed a tear.

The twelve round fight further aggravated the injury, which is now being reported to be a torn rotator cuff. Pacquiao will undergo surgery which is likely going to keep him out of the ring until next year.

Aguilar says the commission first became aware of the injury about 90 minutes before the fight, when Pacquiao's camp made a request for the boxer to get an anti-inflammatory shot on his shoulder, which the NSAC denied because they had no knowledge or confirmation of an actual injury. Arum says USADA [US Anti-Doping Agency] approved the anti-inflammatory medication.

USADA was only a third party to the fight, charged only with testing the fighters for banned substances in training and the night of the bout.

"We had no medical information, no MRIs, no documents," said Travis Tygart, who heads USADA. "It was not an anti-doping issue. The real question is why his camp checked 'no' on the disclosure. Either they made a terrible mistake to not follow the rules or they were trying not to give information to the other side. I'm not sure there's a middle ground."

Tygart said his agency, which was hired by promoters to oversee drug testing for the bout, was contacted April 7 asking about the use of various substances and whether they were allowed under anti-doping rules. He said there was another call 10 days later asking about using a different substance, but that USADA was not told exactly what the treatments were for.

A little more than two hours before the fight, Pacquiao's corner asked Nevada regulators if he could be given a shot of Toradol, an anti-inflammatory. Aguilar denied it, saying the commission had no previous indication there was an injury and could not allow a shot in fairness to the Mayweather camp.

"Our job is to protect the health and safety of fighters and the integrity of the sport," Aguilar said. "We expect our fighters to be forthright."

Nevada State Athletic Commission executive director Bob Bennett said Pacquiao filled out the form himself and understood the questions.

A copy of the form (found below) was posted earlier on the True.Ink website, signed by both Pacquiao and his adviser, Michael Koncz.

"It's not just the fact he didn't fill out the question completely, it was that he wasn't honest and they didn't tell us a month ago when he had the shoulder injury," Bennett said.

"They're not obligated to, but two hours before the fight they wanted a shot that's a pain killer in essence. That put us in a very precarious position."