Hall of Fame referee Joe Cortez is very impressed with UFC superstar Conor McGregor.

Cortez, who retired from being an active referee a few years ago, was retained by McGregor as a teaching tool in training camp.

McGregor is preparing to make his professional boxing debut, against one of the best boxers in the history of the sport, Floyd Mayweather (49-0, 26 KOs). The contest takes place on August 26th at the T-Mobile Arena in Las Vegas.

Cortez was hired to officiate the sparring sessions and to ensure that McGregor was completely familiar with all of the in-ring rules of boxing.

Last week, there was a major bust-up between McGregor and one of his main sparring partners, two-division champion Paulie Malignaggi.

Malignaggi quit the camp after McGregor's team members leaked several photos from a recent sparring session. The photos presented the appearance that Malignaggi got beat up and knocked down. Malignaggi claims that he gave McGregor a beating, which made the MMA fighter "push" him down.

Last week, Cortez confirmed that McGregor and Malignaggi got very physical and very heated during a sparring session, and he was forced to break them up.

Both McGregor and Malignaggi have completely different versions of how that sparring session played out.

Cortez could set the record straight, but Malignaggi claims that McGregor's camp has placed a gag order on the veteran referee.

While Cortez is not willing to discuss the sparring beef, he has no issue with breaking down the event and McGregor's abilities.

"He’s an excellent student, he’s learning real quick. Everything I’m teaching him, he’s learning. This is the biggest fight for him and these guys are making over 100 million dollars a piece. They better abide by the rules and listen to what I’m telling them because we want a good clean fight," Cortez told On The Ropes Boxing Radio.

"I think McGregor brings a lot to the sport. He can punch, he’s a super champion in MMA, he has a lot of talent. Anybody that can punch can be dangerous. If you have a punch, you have a chance too. Anybody that has a punch has a chance because anything is possible. You’ve seen some of the great champions get knocked out in boxing and it can happen because McGregor is a puncher. McGregor is quick with his punches, he hits hard, so anything is possible."