WBO welterweight champion Manny Pacquiao believes UFC superstar Conor McGregor is not “compatible” with boxing and expects the MMA fighter to be beaten in his much-anticipated fight with five division world champion Floyd Mayweather Jr. (49-0, 26 KOs).

McGregor and Mayweather are scheduled to do battle in a Showtime Pay-Per-View main event from the T-Mobile Arena in Las Vegas on August 26, with the undefeated American coming out of retirement in search of a 50th win from as many professional bouts.

Mayweather is an overwhelming favourite for the contest, his stellar career in top-level boxing contrasting sharply with McGregor’s lack of experience in the sport. McGregor has never had a professional or amateur boxing match, but the local commission has no problem with licensing him for the event.

Speaking in Brisbane on Sunday ahead of his WBO welterweight world title defence against Australia’s Jeff Horn, which takes place this coming Saturday night [Sunday in Australia], Pacquiao made it clear he expects McGregor to suffer defeat.

“I can say Floyd Mayweather will win, because the fight is in boxing, not an MMA fight. So that’s an advantage with Floyd,” said Pacquiao. “I don’t think McGregor is compatible with boxing, pure boxing. I’m hoping that it’s not going to be a boring fight. We’ll see.”

Pacquiao’s trainer Freddie Roach would not be surprised to see his fighter face Mayweather for a second time and he's crossing his fingers that it actually happens.

Australia’s Daily Telegraph quoted Roach as saying: “We’ll see what happens, but I think another [Mayweather] fight with Manny could happen.

“Floyd keeps telling people he’s retired then keeps coming back, so there’s a chance.”

Mayweather, who retired back in September 2015 after dominating Andre Berto over twelve rounds, won by unanimous decision over Pacquiao in May of 2015. Their fight was the richest in boxing history, generating over half a billion in revenue and 4.6 million pay-per-view purchases.