by Elisinio Castillo

One of the best pound-for-pound fighters in history, Roberto 'Mano de Piedra' Duran, expects five division champion Floyd Mayweather Jr. to easily dominate UFC superstar Connor McGregor.

Mayweather, 40, will return to boxing on August 26th at the T-Mobile Arena in Las Vegas. For McGregor, it will be his first fight in the sport of boxing. If McGregor really wants to show his skills, Duran says the fighter should go right after Mayweather and break a few body parts.

"Mayweather beats the guy, it will be a spectacle. A wrestler of that size won't do anything to Mayweather. If McGregor is serious he will break both arms and legs of Mayweather. Mayweather will beat him ... McGregor is a clown," said Duran, who was a lightweight, welterweight, and super welterweight champion.

McGregor will never get the chance of doing anything of the sort, because there are clauses in the contract which prohibit the MMA star from doing any illegal moves - or he will face serious financial consequences.

The contract, signed by both athletes, calls for their contest to take place under the rules of boxing with 10-ounce gloves. The agreed upon weight is the junior middleweight limit of 154-pounds.

A lot of experts believe the contest will hurt boxing. Duran disagrees and feels the contest will actually hurt MMA when their biggest superstar is dominated and stopped by a 40-year-old boxer who is coming off a two-year layoff.

"[The fight] will not hurt boxing, but it will hurt mixed martial arts because you're talking about a good world champion [in McGregor], and if that guy loses against Mayweather it should be for something [important]," Duran said.

Mayweather has been out of the ring since September 2015, when he won a twelve round decision over former world champion Andre Berto at the MGM Grand in Las Vegas.