Richard Schaefer has predicted that Canelo Alvarez’s September showdown with Terence Crawford will be "bigger than MayPac."

The former Golden Boy CEO worked closely alongside Floyd Mayweather during his fighting days and was even appointed CEO of Mayweather Promotions in June.

But he has since surfaced as Canelo’s business manager and flanked the Mexican icon during fight week in Riyadh, Saudi Arabia, when he beat William Scull on points at ANB Arena earlier this month.

Immediately after Canelo had beaten the Cuban, following 12 pedestrian rounds, Crawford was brought into the ring as it was officially confirmed by Turki Alalshikh, head of Riyadh Season and chairman of the General Entertainment Authority, that the pair will fight.

The clash will take place on Sept. 13, marking Mexican Independence Weekend, and will be the latest box office smash on Canelo’s resume.

Following his victory over Scull, Canelo, 34, is a two-time undisputed champion at super middleweight while Crawford, who is The Ring's No. 1 at 154lbs, was the first boxer in history to win all four belts in two weight classes (junior welterweight and welterweight).

As such, Schaefer believes a fight between them will hold unusual cultural significance and become the biggest fight since he started working in the sport.

That includes the 2015 mega-fight between Floyd Mayweather and Manny Pacquiao, which was the richest in history thanks in no small part to the staggering 4.6million pay-per-view buys it amassed. He also believes it will eclipse Mayweather's fight with Canelo in 2013 and the Mexican's famous trilogy with Gennady Golovkin.

Schaefer told The Ring: “I’ve been involved since 2000 so that is 25 years and I don’t remember any fight bigger than Canelo-Crawford. It’s going to be the biggest fight in the sport for as long as I can remember.

“With Mayweather-Pacquiao, people hyped it up. It was a big success financially, but I think this can be equally as big of a success in that regard if not bigger.

“But I think Canelo-Crawford is a fight between two men truly in their prime.

“I do believe that experience is going to be a big factor in the fight and I do think size will to a certain extent. Crawford moved up to fight Israil Madrimov and was challenged by Madrimov. Some people even thought Madrimov won that fight and I’ll tell you one thing; Canelo is no Madrimov.

“Canelo has the best chin in boxing, no question about it. He has never been dropped, never been hurt and it’s going to be challenging for Crawford to really hurt Canelo.

“So I think it’s going to be a fascinating match. It’s going to be the biggest fight in modern history. I was fortunate enough to promote Mayweather-Canelo back in the day.

“This will be substantially bigger.”