Mayweather will put his undefeated 49-0 record on the line when he faces McGregor in Las Vegas on 26 August, in a bout which many believe the Irishman has no chance of winning.
McGregor has no professional boxing experience while he is not only facing an undefeated boxer who was on top of the game for over 20 years, but also the best defensive boxer in the sport.
Despite McGregor's physical advantages and youth, it would make no sense for "Money" to lose, which is why Saunders believes the only chance of a win for the "Notorious" was if the bout was fixed.
"It's impossible for Conor McGregor to land a glove on Mayweather," Saunders said, as quoted on BoxingScene.
"This will never, ever, ever happen. The only way something like this would happen [would be] if it was a big fix, and Floyd let him [McGregor] beat him."
While some subscribe to the opinion that Mayweather could tank the fight just to reap the rewards of a lucrative rematch, the undefeated Briton thinks that the legacy of a 50-0 win streak is too much to give up for the potential earnings.
"And that is never going to happen – there is too much legacy," Saunders added. "It is just never going to happen."
"I'm confident enough to say that I'd be willing to let a surgeon cut my heart out, keep it alive and put a £1 bet on that Conor McGregor gets beat in five rounds. And if he don't, then put a knife in my heart."
As for Saunders, the 27-year-old will be in action himself very soon as he will defend his title on 16 September against Willie Monroe Jr. at the Copper Box in London.