A large number of fans and media are not in agreement with Floyd Mayweather's upcoming bout being sanctioned as an official boxing match.

Mayweather will break a two year retirement to face UFC superstar Conor McGregor at the T-Mobile Arena in Las Vegas. Showtime Pay-Per-View will carry the show.

McGregor, a two division champion in the UFC and regarded as one of the best mixed martial arts fighters in the world, has no experience as a professional boxer.

If Mayweather wins, as many expect him to easily do, his record would be raised to 50-0 - which surpasses the 49-0 record of heavyweight legend Rocky Marciano.

That fact has caused a lot of controversy in boxing circles - and it doesn't sit very well with Marciano's son, Rocky Marciano Jr.

Marciano Jr. believes the Mayweather-McGregor bout should have been approved as an exhibition and not as a fully sanctioned boxing match. Marciano Jr. will not be watching the fight and turned down an invitation to watch it at a friend's house.

“No matter what happens, I don’t think it should go towards Mayweather’s professional career (record), win or lose," Marciano Jr. told USA Today. “This fight to me isn’t a true boxing match."

“It’s not a fight that I’m interested in. I see the interest in it, but I don’t think it’ll be an interesting fight."

Marciano won by knockout in 43 of his bouts (87.8 percent) while fighting professionally between 1947 and 1955. He died in 1969 in a plane crash on the eve of his 46th birthday.

“Heavyweights, most of them, hold the highest knockout percentage for a reason,’’ Marciano Jr. said. “They’re bigger, they’re stronger and one punch can take a heavyweight out.

“So it’s a lot more difficult to stay undefeated than it is for someone in the lower weight class, where it can be more of a type of match where you’re just outpointing your opponent.

While Marciano is not happy with Mayweather's ability to raise his record to 50-0, he is a big fan of his talent and says Mayweather has had “an incredible, wonderful, exciting career.’’