Miguel Cotto will seek to make his case as boxing's new top fighter when he takes on Mexican Antonio Margarito at the MGM Grand Garden Arena on Saturday night.

The welterweight division lost boxing's best pound-for-pound fighter when Floyd Mayweather Jr unexpectedly announced his retirement - for the time being, at least - last month.

Puerto Rico's Cotto had hoped to challenge Mayweather, but will instead aim to step into his shoes by downing the exciting Margarito.

A victory over the other top active welterweight in the world will enhance Cotto's already-strong candidacy for the honour with Manny Pacquiao, the recently crowned WBC lightweight champion and a world title-holder in four weight classes, currently considered the world's best boxer.

"If you give me the opportunity to put myself on the scale of boxers, I'm going to put Miguel Cotto at the highest level I can," Cotto (32-0, 26 KO) said.

"But my work is just to train and box. It is the work of the people who know about boxing, the writers, to put Miguel Cotto in the rank they think. It's not my work to put myself on a list. I'm just here to fight, to do my work the best I can."

Cotto's body of work speaks for itself.

His decision to face tough opponents in Zab Judah and Shane Mosley soon after moving up from light-welterweight to win the WBA version of the 147-pound title from Carlos Quintana proves he is not afraid to take on the best fighters out there.

And if the WBA champion beats IBF holder Margarito (36-5, 26 KOs) - whose title is not on the line - he will have defeated four of the top five welterweights in less than two years.

That is in stark contrast to Mayweather, who was accused of avoiding challenges after winning the welterweight titles from Judah and Carlos Baldomir.

Instead of facing either Margarito or Cotto, Mayweather elected instead to meet Oscar de la Hoya at 154 pounds and Ricky Hatton, who moved up in weight and was overmatched in their welterweight title fight.

"Floyd is the most talented welterweight in the world, but Cotto is the most admirable," Hall of Fame trainer Emanuel Steward said.

"He's a guy who always finds a way to win.

We've never seen Floyd in the kind of adversity we've seen Cotto in, and that's not Floyd's fault.

But what it tells you is that Cotto has a tremendous survival instinct."

Cotto's evolution into a complete fighter has not gone unnoticed by his next opponent.

"We have been on a couple of cards together, and I have watched him fight," Margarito said.

"He has gotten better every year. He had a really good run at 140 (pounds) and now 147, and he has turned into a very good fighter."

Unfortunately, Cotto may never have the chance to prove himself against Mayweather.

"If Mayweather is retired, it's all right. We have a lot of big names at 147 pounds," Cotto said. "He disappears from the list and another (replaces him)."

That someone appears to be Cotto himself, and he is expected to rubber-stamp his position with victory against a highly-dangerous and reputable challenger.

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