By Keith Idec

Conor McGregor admits he is impressed by Floyd Mayweather Jr.’s speed, reflexes and experience.

But the boxing legend just isn’t a big enough man to withstand his power, according to McGregor. The UFC superstar assured a group of reporters Friday night that size definitely will matter when the Irish southpaw opposes the heavily favored Mayweather on August 26 at T-Mobile Arena in Las Vegas.

The contract weight for their 12-round boxing match is 154 pounds, a weight Mayweather usually doesn’t even reach when he isn’t training for a fight.

McGregor, meanwhile, fought Nate Diaz twice in 2016 at the mixed martial arts welterweight limit of 170 pounds. He expects to out-weigh Mayweather by 15-20 pounds once their pay-per-view fight starts two weeks from Saturday night.

“He’s too small,” McGregor said after an open workout at the UFC Performance Institute in Las Vegas. “He’s not gonna last. He’s not gonna take the shots. You ain’t never seen me troubled by no small man. You can say what you want. Nate was 200 pounds [in the Octagon]. This man is 150. And if he’s not 150, he’s out of shape. If he’s 154, 155, 156, he’s too heavy.

“He needs to be leaner to be in peak physical condition. One-fifty, I’d say he’s in peak [condition]. So if he comes in any heavier than that, he’s not in peak physical condition. If he comes in at 150, he’s in peak physical condition, but he’s 150 pounds. I’m gonna be 170-plus on the night. I don’t know what else to say. It’s over before it even begins. Trust me on that.”

This is just the fourth fight in the undefeated Mayweather’s 20-year pro boxing career for which the contract weight exceeded the welterweight limit of 147 pounds. The Grand Rapids, Michigan, native has never weighed in at more than 151 pounds for any of his 49 professional fights.

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