Manny have that capability to win back after his defeats but it can only happen if chances to have this rematch and play according to his type of fight and not to allow Mayweather to dictates the tempo of this game, but if same thing will happen like from the last fight it will make it boring and much better not to have the rematch.
The biggest obstacle for Mayweather to have this high level fight after not fighting any good competition for four years is the biggest challenge he will encounter if Mayweather plans to come out of retirement to fight Manny Pacquiao and the only thing that will force Mayweather will be the pay day they are going to earn to make this fight happen, if they fight again the entire fight might gross around a billion dollar and it is not an amount anyone will avoid to have.