Antonio Margarito (left) and Shane Mosley weighed 145.8 and 147, respectively, at the weigh-in for their fight Saturday in Los Angeles. Photo / Tom Hogan-hoganphotos.com

Antonio Margarito and Shane Mosley, who meet Saturday at Staples Center in Los Angeles, are similar in many ways.

They started boxing professionally around the same time, Mosley in 1993 and Margarito a year later. They both toiled for many years before earning universal recognition as stars. Even their styles are comparable in some ways; both are extremely durable action fighters.

However, there is one stark difference: Margarito is 30, Mosley 37. The former is really only arriving; the latter will be leaving soon.

Margarito (37-5, 27 knockouts) was a late bloomer but is now one of the hottest properties in the sport, having brutally knocked out rising star and then-unbeaten Miguel Cotto in 11 rounds in a monumental coming out party in his most-recent fight.

Suddenly, after a series of victories over big-name opponents, the “Tijuana Tornado” – a brawler who wears down his opponents – is considered one of the best fighters in the world and developing a considerable following, most notably among fellow Mexicans.

If he continues to win, particularly in a rich welterweight division, there’s no telling how big he’ll become. A mega-rematch with Cotto is already set for June if he wins Saturday and Cotto beats Michael Jennings on Feb. 21.

And Margarito has no doubts about Saturday.

He won’t buy into the Mosley-has-declined argument. He typically doesn’t focus on his opponents. Instead, he sticks to his not-so-secret weapon: extremely hard work before and during the fight.

“I don’t see any advantages (over him),” Margarito said through an interpreter. “I just think that my preparation, the way I work, the way I always come prepared to fight, will carry me through. ÔǪ I think he’s a great fighter, a great champion. I don’t underestimate him.

“I just come in thinking this is my moment, my time to shine.”

A victory over Mosley (45-5, 38 KOs) would be a nice entry on Margarito’s resume because of the older fighter’s name recognition; he, too, knows what it’s like to be ranked among the best fighters in the world pound for pound.

That’s in the past, though. No one is describing this as an utter mismatch, in part because Mosley remains quick and tough, but he seems to have declined with age.

Mosley looked good against Cotto in November of 2007, pushing the Puerto Rican star to the limit before losing a close decision. However, in his most recent fight, against Ricardo Mayorga in September, he had none of his old fire and looked vulnerable.

Mosley was able to finish Mayorga off, stopping him in the final round, but impressed no one until that moment.

Compare the CompuBox stats. Against Cotto, Mosley threw 774 punches, a healthy 64.5 punches per round. Against, Mayorga, who is no defensive wizard, Mosley threw only 372 punches going into the final round, a 33.8 average. That’s roughly half the output.

Immediately after the fight, during a conversation about a Margarito-Mosley fight, several observers shuddered. This faded version of Mosley, they concluded, would have no chance against a stud like Margarito.

Yet here we are, on the cusp of that very fight. And, as experts do, they concoct ways that each fighter can beat the other.

In this case, the conventional thinking is that Margarito will break down Mosley with incessant pressure just as he did against Cotto and so many others. In the end, consensus has it, he will either stop Mosley late in the fight or win a decision.

If that happens, particularly if the fight is one-sided, it’s difficult to imagine the four-time world titleholder remaining a major player in the sport. He would be 7-5 (with one no-contest) in his last 13 fights, hardly the record of a star.

Those who think Mosley can win say he has the right style for Magarito. They reason that Mosley is a quick, talented boxer who can build up points but also is resilient enough to survive Margarito’s pressure for 12 rounds. Mosley has never been knocked out.

If Mosley can build a lead early in the fight and then hang on, who knows? He could pull off what would be his first major victory since he outpointed Oscar De La Hoya in the same arena in 2000. (Mosley did the same in their 2003 rematch but later admitted to have taken performance-enhancing drugs prior to the fight.)

In the days leading up to this fight, Mosley seemed to be confident and in very good spirits in spite of the doubters and personal problems – firing his father as his trainer for a second time (and hiring Naazim Richardson), splitting with his wife and fending off questions about his use of the drugs.

At the final media conference on Thursday, he seemed to be almost giddy.

“I can’t wait to get into the ring, I just can’t wait,” he said. “I’ll let Margarito speak and say his peace but I believe I’ll be victorious. I trained very hard. A lot of people are going to be surprised when they see the result of this fight.”

Michael Rosenthal can be reached at [email protected]