By Keith Idec

LAS VEGAS – Conor McGregor recognizes just how much damage he could do to the sport of boxing Saturday night.

If the UFC superstar were to upset Floyd Mayweather Jr. in McGregor’s first official boxing match, it wouldn’t just be an incredible victory for the brash Irish showman and the sport of mixed martial arts. It also would be a devastating defeat for not only Mayweather, but the entire sport of boxing.

To say that a complete novice beating the best boxer of this generation would be bad for the public’s perception of the boxing business would be a massive understatement. McGregor continued to promise Wednesday during their final press conference – tame compared to their circus-like, four-city press tour last month – that he’ll knock out the undefeated, 40-year-old Mayweather within two rounds.

He also told Mayweather (49-0, 26 KOs) and everyone else that thinks their 12-round, 154-pound fight will amount to more “easy work” for the legendary boxer that Mayweather made an egregious mistake by agreeing to fight him.

“I’m gonna f*** this boy up,” McGregor said. “Make no mistake. And when it’s all said and done, you know what? I’m gonna feel a little bit sad. Because you should’ve all kept your mouth shut. You should’ve left me in that other game that I’m from, that more ruthless game, where we bounce heads off the canvas and drill them into the floor. You should’ve left me where I was because this man is not on my level. He’s not even a quarter of the man I am. So we’re gonna see and you’re all gonna eat your words in there.”

Mayweather remains slightly more than a 5-1 favorite, even though he is coming off nearly a two-year layoff and McGregor is 11 years younger than him. Ireland’s McGregor is undeterred as he prepares for his boxing debut at T-Mobile Arena (Showtime Pay-Per-View; $99.95 in HD).

“We are prepared for 12 three-minute rounds of non-stop pace,” McGregor said, “and I will go forward and I will put the pressure on him, and break this old man. Trust me on that.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.