Conor McGregor calmly and rationally accepted Floyd Mayweather's critique of his current weight is a sentence that will never be uttered. After Mayweather implied on Tuesday that McGregor looks big and might not make the 154-pound weight limit for Saturday's fight -- possibly being 10 pounds over the limit -- McGregor snapped back at Mayweather the only way he knows how: Loudly and to the press.

"Tell him to shut his f---ing mouth," he told reporters. "He knows nothing, fool of a thing. Let him keep praying. Praying for fatigue. Praying for me to take a back step. All he's doing is praying, but he's praying to the new God of boxing."

McGregor, who called himself the UFC champion and future boxing champion on Tuesday, hasn't been modest about his odds. He also said that his weight is "absolutely phenomenal, like it always is" ahead of the fight, which will air live Saturday at 9 p.m. ET on Showtime PPV.

On Tuesday, Mayweather said that didn't believe McGregor would make weight. "Even if he does make the weight, that's even better, but if he doesn't make the weight, we're still gonna fight. But it's gonna be a heavy fine. Gimme that money," he said.

Mayweather hasn't been shy about his reasoning for this fight. He wants to get paid, and winning is his bonus. His trash talk has been in line with his more recent fights -- relatively tempered -- a stark contrast to the loudmouthed McGregor (McGregor also stands as a heavy juxtaposition to Mayweather's last opponent, the relatively mild-mannered Manny Pacquiao).

There are two places making fun of weight is considered a good burn: a boxing match and a "Mean Girls" script. This fight has had barb after barb with neither fighter backing down. McGregor definitely has the edge in enthusiasm, which is in line with his bombastic nature, but how the fight plays out on Saturday remains to be seen.