AFP - Philippine boxing great Manny Pacquiao has opened the door to a lucrative rematch with Floyd Mayweather, telling AFP he still intends to retire after his next fight but that a comeback is possible.

The 37-year-old announced in January that his upcoming bout against American Timothy Bradley would be his last so he could concentrate on Filipino politics.

However, following a high-energy training session in his hometown of General Santos, Pacquiao said he loved the sport as much as ever and he could not rule out fighting again.

"It's hard to say right now," Pacquiao, who has won world titles in an unprecedented eight weight divisions, said when asked about retirement.

"I made my decision already that after this fight I (will) retire. But I am not saying that, you know, boxing is closed to me. You never know."

Pacquiao made the comments when asked if a chance to avenge his crushing loss to American nemesis Mayweather last year would lure him out of retirement.

That fight shattered boxing revenue records, generating 4.5 million pay-per-view purchases and $600 million (S$843 million) in gross revenue.

He said Tuesday his shoulder had recovered and he was in "100 per cent" condition to take on Bradley.

After overseeing training on Monday, long-time American mentor Freddie Roach also said he suspected Pacquiao would be tempted back into the ring if he beats Bradley.

"I'll go along with him right now because he is running for Senator," Roach told AFP, when asked if he believed Pacquiao genuinely intended to retire.