there's no way he would have lost weight for the role. and keach was great. but what if brando had got his act together and played the role. the film would have been something else. dont get me wrong, keach was great.
shareThough Marlon Brando was reasonably young around 1972 -- he would play The Godfather at age 47 as a 60-something man and thus look "surprisingly young" without the make-up -- I don't see Brando being able to do this role.
Its funny: around the same time as The Godfather, Brando made movies before it and after it (The Nightcomers and Last Tango in Paris) in which he went a little bit nude and very shirtless and looked OK - he was not yet the overweight Brando of his last decades.
But "fit" for sex scenes is not "fit" for boxing scenes and no, I don't think Brando could have done the Keach role. You can see Huston's thinking -- "Brando was a young fit boxer in On the Waterfront -- how great would it be to see him as a broken-down older boxer here?"
Also around this exact same time, Brando was evidently at least considered for the Burt Reynolds role in Deliverance. Again -- I can't see it. As the movie showed, this role required a young, fit, strong man and Brando in his forties had simply aged beyond it. (I've read that Henry Fonda was considered for the Jon Voight role, opposite Brando. The same kind of craziness.)
What's funny is that very often, "Hollywood as Hollywood" often tried to cast big names when they were past their prime. Another example is Cary Grant, who kept get offered roles meant for much younger men.
If Brando had played Tully it wouldn't have been half the movie it was with Keach.
shareIf Brando had played Tully, then would he have been able to play Vito Corleone too?
If Brando did get the role, then one benefit is that the movie would have won more recognition. Today, this movie has been kinda lost to history. I also believe the money was a box-office bomb
Keach did well. But I do think Brando would have done well too.