Manny Pacquiao's trainer Freddie Roach believes the Filipino would beat Floyd Mayweather if he got another chance against the undefeated American.
Pacquiao was beaten on points by Mayweather when the pair met for the first time in May in the 'fight of the century'.
However, Roach reckons Pacquiao would have won that fight had he not been hampered by a right shoulder injury and has backed his man to come out on top should they meet again.
The sticking point, though, is that WBC and WBA welterweight champion Mayweather has said he will fight for the final time when he takes on Andre Berto in Las Vegas next month.
Mayweather Promotions chief executive Leonard Ellerbe has also said the 38-year-old will bring the curtain down on his glittering career on September 12.
However, if Mayweather wins that fight - he is quoted at 1/100 to prevail by Sky Bet - it will take his record to 49-0, and Roach expects him to carry on boxing until at least his 50th fight.
Manny would do much better in a rematch, if the shoulder gets better... I do think we can beat Mayweather, 100 per cent.
Pacquiao should be ready to fight again next year after recovering from his injury and Roach would relish another shot at Mayweather.
Roach told Boxing News: "I don't know where Mayweather's going right now. I don't think he will stop at 49 fights, I think he'll fight to 50. I'm hoping that he promotes himself, maybe if he does he can make more money.
"Manny would do much better in a rematch, if the shoulder gets better. We were doing well until the shoulder went in the fourth round and we had a tough time after that. I do think we can beat Mayweather, 100 per cent."