by Keith Idec

Marcos Maidana might be a big underdog Saturday night, but Floyd Mayweather Jr. respects the rugged Argentine brawler’s power.

“Well, it’s obvious he punches extremely hard,” Mayweather said recently while promoting their welterweight title fight at MGM Grand in Las Vegas. “He has an 80-percent knockout ratio. It’s obvious that’s his best attribute. But, you know, a lot of times when a guy’s swinging a lot of big shots and they’re not landing, you get fatigued like that.”

Mayweather (45-0, 26 KOs), a Las Vegas resident raised in Grand Rapids, Mich., hasn’t been noticeably affected by an opponent’s power since Shane Mosley rocked him with a right hand that left Mayweather holding during the second round of their May 2010 bout at MGM Grand. Mayweather came back strong following that trouble in the second round and dominated Mosley.

The 37-year-old Mayweather won’t know, though, if anyone has hit him harder than Maidana, 30, until Maidana (35-3, 31 KOs) actually lands punches on him.

“Well, I can’t really say,” Mayweather said. “I haven’t been hit by Maidana yet, so I can’t really say. I may be the hardest puncher he’s ever fought. He hasn’t been hit by me yet, so we’ll just have to see if he’s the hardest puncher.”

The Mayweather-Maidana fight will headline Showtime’s four-fight pay-per-view telecast, which will begin at 9 p.m. ET/6 p.m. PT and will cost $74.95 to watch in HD.

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com. He can be reached on Twitter @Idecboxing.