Once upon a time Floyd Mayweather Jr. ruled the professional world of prizefighting at the top of the rung. But he retired.

The Las Vegas-based fighter, who temporarily departed 20 months ago as the recognized best fighter in the world Pound for Pound, is back again and this time he faces Mexico’s Juan Manuel Marquez who most experts consider the second best fighter Pound for Pound, behind current leader Manny Pacquiao.

A rib injury suffered while preparing for a July 18 date scuttled the fight temporarily, but Mayweather and Marquez both say they’re ready to clash on Sept. 19, at the MGM Grand in Las Vegas. The fight will be shown on HBO pay-per-view.

Lots of questions remain for Mayweather in particular, can he return to form after the lengthy absence? Will he be fighting at 143 as first suggested or 147? Should he be considered the best despite his absence? Can he sell more pay-per-views or tickets for that matter than the former king Oscar De La Hoya? Is he truly the best though he hasn’t fought Shane Mosley, Manny Pacquiao, Paul Williams or Miguel Cotto?

Another set of questions exists too. Is he really near bankrupt as has been published by various media organizations? Was he really hurt by a sparring partner?

First off, Mayweather seems earnest in his willingness to get back in the ring against smaller but formidable Marquez.

“With the layoff that was a good thing. When I was training a little while back I was pushing myself to the limit,” said Mayweather. “I’m anticipating getting back in the ring. It’s making me work so hard. I’m waking up at 4 in the morning.”

With about a month to go in the first scheduled encounter Mayweather postponed the fight due to a rib injury. According to various sources in the gym at the time it was junior middleweight Juan Pablo Montes De Oca who zapped him with a body shot and injured the undefeated fighter.

Mayweather is not telling.

“I got hurt in training and I’ll leave it at that. I don’t have to go in depth in what happened to me,” Mayweather said.

Mayweather said that Marquez is a good fighter and does not want to slip like De La Hoya against Manny Pacquiao last December.

“When De La Hoya was in training preparing for a fight he was focused more on losing weight than focusing on fighting,” said Mayweather about the loss by De La Hoya to the much smaller Pacquiao. “He was only training when (HBO) 24/7 come around. You got to take this sport seriously. Sometimes chasing money can mess your whole career up.”

Mayweather is adamant that underestimating Marquez will not occur.

“Marquez is a Mexican warrior, he represents himself and the heritage extremely well. What I got to do is be me and box smart,” Mayweather says.

From Mexico City, Marquez spoke to the media, displayed a calm demeanor and seemed not upset at the postponement. Serenity at being near the biggest fight of his career seems paramount to quibbling over a change of dates.

“I was peaceful. I knew that it was just a misstep. I was ready but I remained calm. Whatever happens I know this sport, you know that injuries are a big part of any sport. I just had to stay calm and now I’m getting ready again,” said Marquez.

A time existed when Marquez was one of the most avoided featherweights in the world. It took more than a decade to finally get Marco Antonio Barrera in the ring. He never did lure Erik Morales. Now he’s moving up to the welterweight level after skipping entirely the junior welterweight division. It’s a big, big risk.

“I believe this is the hardest fight of my life. I have to box intelligently,” Marquez said during the telephone conference call on Tuesday. “I’m putting all the ingredients together in my game plan so I can beat Mayweather.”

Mayweather never claimed an easy win but truly believes he is unbeatable despite not fighting for such a long period. He showed a tint of anger with Shane Mosley and Pacquiao who are considered rivals for the Las Vegas fighter.

“I feel Manny Pacquiao is a good fighter. When he goes out there he does his job,” Mayweather said. “Manny Pacquiao got beat by Erik Morales and I stayed on the top of the game and I never got beat.”

He also suggested that Pacquiao should not have turned down a contract to fight, that if you look at the financial figures it points that a Mayweather fight in the last three fights made more than Pacquiao in his last three fights. Even when they fought the same opponents in De La Hoya and Ricky Hatton.

The point was backed up by Golden Boy Promotions CEO Richard Schaefer who is co-promoting the fight.

“Floyd Mayweather in his last two fights generated more than the last five Pacquiao fights combined. That’s a fact,” said Schaefer.

Regarding Mosley, he accused the Pomona-based fighter of cheating and suggested he is still cheating and “still taking steroids.”

“These fighters know they can get a pay day with me,” he said.

Marquez seems content to take a back seat to Mayweather’s high jinks and feels fortunate to be in a position to finally make a fortune while simultaneously making a claim as the best fighter in the world today should he win.

“I’m getting ready for the best Mayweather ever. I not thinking about his retirement,” said Marquez when it was suggested that Mayweather may not be at his best. “I’m thinking of beating the best fighter in the world.”

Mayweather said an upset will not happen.

“All jokes aside. I can’t overlook this guy,” said Mayweather. “Guys like Marquez deserve a shot so he can make some money.”

Deaths of Arturo Gatti and Alexis Arguello

“Alexis Arguello was sheesh, one of the best junior lightweights to ever put on a pair of gloves,” said Mayweather. “Gatti never turned his back on no opponent. He would get knocked down four, five times and come back with one shot. He was a throwback fighter.”