Floyd Mayweather has labelled Conor McGregor a “dirty” fighter and fears the Irishman will use MMA-style tactics to try and win their boxing match on August 26.
The boxing champion, who has a 49-0 unbeaten record added that he is taking the biggest risk in their hugely anticipated bout because of his 20-year winning streak.
"I'm taking the biggest risk, but it is a big reward for both," said the five-weight world champion.
"I have the 49-0 record. If you have lost before it's OK, but if you are 49-0, as I am, everything is on the line."
Mayweather added that he believes the UFC fighter could potentially use MMA-style tactics during the fight.
He said he had watched the clips of McGregor sparring with former world champion boxer Paul Malignaggi.
"I see a lot of rabbit punches behind the head, grappling, wrestling, illegal shots,” Mayweather told journalists on an international media conference call.
"Some may call that a KO, but it doesn't matter as it is just in the gym. What counts is in the ring. Paulie has retired and he is now commentating and traveling around the world. McGregor is active and hard in training.
“But the ref will be fair on both sides, I want him to be even. I want us to have a good solid fight.”
— MayweatherPromotions (@MayweatherPromo) August 6, 2017
McGregor’s contracts stipulates he will be penalised financially if he uses any MMA-style moves such as kicks and elbows.
The 40-year old boxer added that he had faith in referee Robert Byrd, who was appointed by the Nevada State Athletic Commision to referee the fight on Thursday.
“I truly believe Robert Byrd is going to do his job, his job is to keep the bout clean,” Mayweather said.
“We are going to have a hell of a fight. Like I have said, I am coming straight ahead.
“I look forward to following the Queensberry rules of boxing. McGregor had referee Joe Cortez in his training camp but I still see him being extremely dirty. But my job is not to referee the fight, I am going to do my job. I am not worried about the outcome, I am more worried about excitement.”