Conor McGregor

UFC fighter McGregor enters a boxing ring for the first time to take on the unbeaten Mayweather on August 26.

Few in boxing circles are giving the rugged Irishman much hope.

But Holmes, a former world heavyweight champion who keeps a keen eye on the game, feels McGregor has a real chance if he can fight intelligently.

"Don't sell McGregor short, he doesn't have to do too much to win," Holmes told the Bald Faced Truth radio show in the United States.

Mexican star Saul 'Canelo' Alvarez – preparing to step into the ring with Gennady Golovkin – said he might be willing to fight McGregor, but only if he is able to beat Mayweather on August 26.

"If that miracle was to happen, then we have a conversation," Alvarez told Fansided.

"If that miracle were to happen, but I doubt it very much that Conor beats Floyd."

Alvarez would know a thing or two about trying to beat Mayweather. The only time he has lost in his 51 career matches was against the undefeated American in September 2013.

UFC champion McGregor will step out of the octagon and into the ring to fight unbeaten boxer Mayweather in Las Vegas on August 26.

Many have weighed in on who will win the hyped fight and now Tyson has voiced his opinion as Mayweather puts his perfect 49-0 record on the line against the unproven Irishman.

"McGregor is going to get killed boxing," Tyson told Barstool Sports on Monday. "Boxing? I got mad because I thought they were going to use MMA rules against boxing because that's what it's all about: Can the boxer beat the MMA guy?"

Australia's Horn, who this month beat Manny Pacquaio to win the WBO welterweight title in Brisbane, has called out the 40-year-old five-division world champion.

But Mayweather ruled out any prospect of a fight with the former Queensland schoolteacher in front of a packed press conference in London on Friday, saying he'll hang up his gloves after facing McGregor on August 26 in Las Vegas.

"This is my last fight," Mayweather said.

"I've just done years and years and years of just fighting and travelling.

Few athletes could demand and capture our attention in consecutive nights armed with just microphones. Fifty thousand people congregated in four cities across three countries to see two men who uniquely transcend sport and entertainment, with their 'world tour' of press conferences generating over eight million views on the official YouTube link alone by Friday night. Such popularity, for anybody still questioning this fight's validity, is why Floyd Mayweather vs Conor McGregor is happening.

Former WBA welterweight world champion Malignaggi, who retired after being stopped by Sam Eggington in March this year with a record of 36-8,previously called out McGregor and labelled the mixed martial arts fighter's boxing match with Mayweather a must-see.

The pair have been trading verbal blows for months and a deal has been a long time coming despite both men stressing they were keen for the fight to take place.

However, that all changed on Wednesday after the Nevada State Athletic Commission approved a request put in by Mayweather Promotions to host a boxing match in late August.

Soon after, both Mayweather and McGregor took to social media to confirm the fight will take place, a move that will send shockwaves through both boxing and MMA.

Speculation that UFC star McGregor and retired five-weight world champion Mayweather could meet under Queensbury rules has been growing on a daily basis.

Mayweather, who is arguably the greatest boxer of his generation, wants to unretire to take on McGregor, who is the first man in history to hold two UFC titles simultaneously.

Speculation regarding the potential superfight has been building steam for months but the situation is complicated by McGregor's contract with the UFC, who would have to sign off on any deal.

Mayweather urged MMA star McGregor to stop "crying" about money and sign terms with his UFC bosses, so the pair can meet in a cross-codes fight this summer.

The five-weight world champion told fans he was tired of hearing excuses from McGregor when he appeared at Liverpool's Auditorium on his latest leg of his UK Undefeated Tour on Friday night.

"When I faced Arturo Gatti, I went to his turf and he was the A-side I was the B-side," said Mayweather. "I beat him and I didn't cry or I didn't complain.