By Joseph Santoliquito

Philadelphia, PA (CBS)—The face of boxing turned 37 a few weeks ago, and in this brutal sport, that’s almost ancient. But you can’t tell by Floyd Mayweather’s countenance. It’s not weather beaten and scarred. His face is almost as pristine as it was 16 years ago when he began his professional career.

Call this the twilight of Mayweather’s countdown tour. The pound-for-pound king announced that he’s going to take on power puncher Marcos Maidana on Saturday, May 3 at the MGM Grand in Las Vegas on Showtime PPV.

It’s the third installment in his record-breaking six-fight, three-year deal with Showtime. And still at 37, nothing appears to be able to stop Mayweather (45-0, 26 knockouts), even at an age when most fighters have passed their prime.

Not Mayweather.

He maintains he hasn’t yet reached his peak, despite destroying Canelo Alvarez last September. The 30-year-old Maidana (35-3, 31 knockouts) is coming off the most impressive victory of his career, in December vanquishing Adrien Broner, touted by some “the next Mayweather,” in his last outing.

There was strong speculation that Mayweather would hand pick England’s Amir Khan as his next opponent. But to his credit, Mayweather opted for the bigger challenge.

“Maidana is young, strong and a tough competitor,” Mayweather said. “You can never take any fighter for granted, because anything can happen. Look at his last four fights [three knockouts, two knockdowns in the Broner decision] and look at [Amir] Khan’s last four fights [two losses]. He’s made a big impact on the sport of boxing in his last fight. He hits with both hands. He looked tremendous [against Broner]. I had to go with the best choice.”

Whether or not Maidana could do what 45 previous opponents failed to do is unknown. Though, it is highly unlikely Maidana will cause Mayweather any serious problems. Maidana got to Broner. But where Broner aspires to be Mayweather, he’s not. Maidana will charge forward and try to make it a fight. Mayweather will use his considerable speed and fast hands to chop away at Maidana.

It could be as lopsided as most of Mayweather’s fights usually are. That, however, is not how Mayweather judges things.

He sets his own standards.

“I’m a strong critic of myself.” Mayweather said. “Even with the Canelo fight and fight before that I wasn’t happy with my performance. I’ve been in the sport a long time, but I haven’t been able to bring my A game totally out. I’ve beaten fighters with my C game and D game, but I haven’t been able to beat anybody with my A game.”

And many will pay to see Mayweather, despite the level of risk. Case in point: Alvarez-Mayweather generated a record $150 million in sales.

Of course, Manny Pacquiao’s name had to be broached about a possible September date on Mayweather’s docket. But because of the ongoing feud between Golden Boy Promotions, which has promoted Mayweather’s fights since 2007, and Bob Arum’s Top Rank, which promotes Pacquiao and which Mayweather once had an acrimonious relationship with, that fight may never be made.

“Floyd Mayweather’s not scared of any opponent, I’ve earned my stripes and fight who I want to fight,” Mayweather made sure to express. “Nobody is forced to watch. [Maidana] is tailor-made to make a war.”

Joseph Santoliquito is a contributing sports blogger for CBS Philly.