Hall of Fame trainer Freddie Roach is still optimistic that the super fight between Floyd Mayweather Jr. and Manny Pacquiao will eventually happen before both fighters hang up their gloves.

Roach told On The Ropes Boxing Radio last weekend that Mayweather will have no choice but to face Pacquiao in one of his remaining fights because the reigning pound-for-pound king is running out of opponents.

"Well the thing is they are running out of opponents and I think somewhere before the last fight in his contract, he's gonna have to cross over and fight Pacquiao," Roach said.

One of the possible road blocks is the promotional dispute between Top Rank, Golden Boy Promotions, and Mayweather Promotions, but Roach expressed confidence that the companies will find a common ground.

Roach, who said that Pacquiao is very willing to face the reigning WBC welterweight champion, is also convinced that HBO and ShowTime will settle their differences to make the potential record-breaking showdown happen.

"So you know, Top Rank, Showtime, Golden Boy, HBO and all that - the pool's getting smaller, so someone's gonna have to give in pretty soon because there are no opponents in the future. Pacquiao is available and waiting, and if he doesn't have an opponent we're definitely willing to fight him," Roach said.

Mayweather is currently preparing for his upcoming showdown with Marcos Maidana on May 3 at the MGM Grand in Las Vegas, and could face Amir Khan in his next fight, possibly in September if the Briton beats Luis Collazo.

Roach said that while Mayweather and Pacquiao will be remembered as two of the best boxers in history, both fighters' legacies will be questioned if they don't end up facing each other.

Roach added, though, that Mayweather's legacy will be affected more than Pacquiao's reputation, especially if the Grand Rapids native retires undefeated without facing Pacquiao.

"You might get some people being skeptical about why they didn't fight but I think it will hurt Mayweather more than us because he's the one that's so proud of his undefeated record, but he didn't fight the best challenge and that's Pacquiao," Roach said.