Philippine boxing great Manny Pacquiao has opened the door to a lucrative rematch with Floyd Mayweather, saying 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 was loving 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 in an interview 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 in gross revenue. It capped a phenomenal rise for Pacquiao, whose journey from street kid to mega-rich athlete is a source of hope and inspiration for tens of millions of poor Filipinos. Until this week, Pacquiao had insisted repeatedly that he was very happy to be giving up the sport to pursue politics and his goal of fighting poverty in the Philippines. Pacquiao, a two-term congressman, is looking to win a Senate seat in May elections, and the official campaign is already underway. Pacquiao spoke at length Tuesday about his political aspirations — including the prospect of becoming president. And he repeated that, at this point, his intention was to retire from boxing after fighting Bradley for the third time in Las Vegas on April 9. But Pacquiao also indicated he wasn't sure his retirement would be permanent, twice using the term: "You never know." He also insisted he remained as physically capable in the ring as a decade ago. "I don't feel different compared (with) when I was 27, 25," Pacquiao said. "I am still the same because I discipline myself. Even if I don't have a fight and I am not in training, I always exercise every day." Pacquiao aggravated a shoulder injury in the Mayweather bout and underwent surgery five days later. He said Tuesday his shoulder had recovered and he was in "100 percent" condition to take on Bradley. After overseeing training 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 said, when asked if he believed Pacquiao genuinely intended to retire. "But there's always that side of me that sees Senator Pacquiao (fight again). Because he likes that, he loves stuff like that," Roach said. Pacquiao is on track to win one of 12 Senate seats in the elections, according to recent surveys, with his sporting heroics largely responsible for his political popularity. However, success is not guaranteed. Pacquiao has been heavily criticized by some in the Philippines for a dismal attendance record as a congressman that they argue highlights a lack of political conviction. Pacquiao also apologized via social media Tuesday after saying on the campaign trail that homosexuals were "worse than animals." After a barrage of criticism, Pacquiao asked for forgiveness.