Boxers Juan Manuel Marquez, right, of Mexico, and Floyd Mayweather Jr. face off during a news conference at the MGM Grand in Las Vegas. Photo Credit: Jae C. Hong / AP Photo

There is nothing quite like shutting up the constant flapping of an open mouth in the sports world.

And in the world of boxing, many have had their traps smacked shut — even wired shut. The sweet science has been a pit of judgment for countless fighters who disrespected their opponent and the sport, enraging hard-core fans in the process.

Fernando Vargas called Oscar De La Hoya and his handlers the “Peter Pan Squad,”  and his the “Ferocious Squad.” Did that make Vargas Captain Hook? Well, the only hooks that were thrown that night were the ones that put him down, humbling his thug image and taking away his street cred.

Ricardo Mayorga, what was he doing on the floor less than a minute into a fight? It was adios y buenas noches, courtesy of a De La Hoya left hook so violent and fast Mayorga didn’t realize what had happened.

Zab Judah, who crowned himself the everything of the sport, was then hit so squarely on the chin by Kostya Tszyu that he literally turned to walk away, mumbled a couple words and collapsed seconds later.

Get the picture? The boxing ring is where all debts are due. All checks written with a cocky and filthy mouth are cashed with fists to the face.

And nearly every fighter’s day of reckoning comes.

This Saturday night in Las Vegas is Floyd Mayweather’s day of shutting up will be at hand. “Money” Mayweather, or “Pretty Boy” Floyd — whatever he wants to call himself (since he is his biggest fan) will step into the ring with Mexico’s latest top fighter Juan Manuel “Dinamita” Marquez.

The same Marquez who fought Manny Pacquiao to a draw in their first fight and lost on points by split-decision in the second. If Pac Man is boxing’s best pound-for-pound fighter, then what does that make Dinamita?

Mayweather constantly brags about the amount of cold, hard cash he carries around and how people just don’t know how to, “step their game up,”  like he does. In other words, he lives lavishly and flaunts what he has.

But can he honestly boast about battles he has fought in the ring? Can he say he has fought wars in the ring, the kind of wars that take a fighter to the depths of combat? He retired under the convenient premise that there was no one out there left to fight — no legitimate opponents.  Try running that statement by Shane Mosley, Miguel Cotto or Pacquiao.

As seen in his biggest fight against De La Hoya, Mayweather is the typical talker outside the ring and survivor in it. He went in trying to out-point De La Hoya, to get a victory on the judges’ scorecards. De La Hoya tried to press the action, but Floyd wanted no part of any exchanges. Floyd simply got enough points here and there in the later rounds to be awarded the decision.

The few times he has crushed his opponent have come when he faced clearly suspect elite fighters. Hello and goodbye, Ricky Hatton.

But Marquez’s pedigree is not suspect. He has gone to battle with Pacquiao twice, Marco Antonio Barrera and Juan Diaz. Judges will often grow tired of a fighter moving away from action and not exchanging shots. Marquez will press the action and will be the aggressor — but he won’t walk into punches like Hatton did.

“Money” likes to show how much cash he has, and Saturday he will pay the bill — only it won’t be paid in dollars, it will be paid in humility.