Veteran referee Joe Cortez says Kenny Bayless should keep an eye on Floyd Mayweather's elbows on Saturday night.

The Puerto Rican veteran said on Friday Bayless, who will be in charge of the American’s welterweight fight against Manny Pacquiao, would have to be on guard if Mayweather resorts to raising his elbows.

"Floyd is not a dirty fighter by nature," Cortez said. "But when an opponent begins to get to his head from in front, he will raise his elbows to defend himself.

"Kenny Bayless must be very careful that when Floyd raises his elbow he doesn't cut Pacquiao and force the bout to be stopped and Mayweather [to be] disqualified. That would be disastrous."

Visiting the press tent in Las Vegas on Friday, Cortez was mobbed by reporters wanting his opinion on how the fight would unfold.

The 70-year-old Hall-of-Famer said he remembered well the four Mayweather fights he worked.

Cortez feels the American is one of the best counter-punchers in the game. "He is clearly one of the best stylists in the ring, with great defence and intelligence. It will not be easy for Manny to solve his style."

Bayless knows both Mayweather and Pacquiao well. He has refereed seven of the Filipino's fights, including those against Shane Mosley, Ricky Hatton, Miguel Cotto and Juan Manuel Marquez, and five of Mayweather’s.

Bayless refereed Mayweather's first professional fight, on October 11 1996 when he won against Mexican Roberto Apodaca.

The 64-year-old physical education instructor and former boxer has been a professional referee for 24 years and has handled more than 100 title bouts.

Although Oscar de la Hoya said Bayless "always favours Mayweather," Pacquiao’s trainer, Freddie Roach, was happy with his appointment. "Bayless is now the best in the business." Roach said.

Roach also approved the appointment of Burt Clements, Dave Moretti and Glenn Feldman as judges.

"I think we have the best judges and Kenny Bayless is the best referee here, and that guarantees a fair fight," Roach said.