Carl Frampton has said Conor McGregor will do well to lay a glove on Floyd Mayweather in their Las Vegas superfight, but Donegal middleweight Jason Quigley has predicted the Dubliner will knock his opponent "out cold".

McGregor's long-mooted collision with the 40-year-old was finally confirmed by both camps on Wednesday night, with a 26 August Las Vegas showdown set to land in a cloud of hype and feverish interest.

The biggest draw in the UFC will enter the ring with perhaps the finest boxer of his generation in a unique contest that has divided opinion.

Frampton - preparing for a WBC world featherweight title eliminator against Andres Gutierrez in July - can't see anything other than a comfortable Mayweather win,

"I think it's a bit unfair because boxing and MMA are two different sports and Conor McGregor, if I'm being blatantly honest, if he lands a glove on Mayweather he'll be doing very well," said the Northern Irishman.

"Mayweather makes fighters like Manny Pacquaio and Canelo Alvarez look very ordinary. I don't think McGregor has the boxing prowess to do anything with Mayweather.

"It's unfair, it's two different sports but both of them will make a lot of money out of it and even Conor probably knows that himself.

"It's a bit of the old WWE sort of stuff, razzmatazz. If it happens both guys will make a lot of money, but Mayweather wins."

Last November, Quigley said he'd be more than willing to lend his expertise to the McGregor camp if the fight was to happen, and now the US-based 26-year-old is predicting a stunning success for his compatriot.

"People will think I'm crazy and people will go mad about this but, mark my words, Conor McGregor is going to knock Floyd Mayweather out cold," he told Sky Sports.

"You’ve heard it here first. Conor believes it, I believe it and Ireland believes it.

"Floyd is moving on in his career, he’s getting past it a little bit now. He keeps himself well, don’t get me wrong, but Floyd Mayweather won’t hurt or won’t damage Conor McGregor.

"In the UFC, the stuff they go through on the ground with knees and elbows, everything, I think Conor McGregor is definitely going to open a lot of eyes.

"He’s going to make history and be the first man to knock Mayweather out cold."