Floyd Mayweather Jr. and Marcos Maidana will square off in a rematch on Sept. 13 at the MGM Grand in Las Vegas, and this early, the two fighters are already trading verbal jabs.

In a press conference on Monday in New York, Mayweather said that Maidana fought dirty in their first showdown, saying that the former WBA welterweight champion is incomparable to his previous opponents like Saul "Canelo" Alvarez and Miguel Cotto.

"Is Maidana a better fighter than Canelo? No. Is he a better fighter than Cotto? No. Is he a dirtier fighter? Yes, that's safe to say," Mayweather said via BoxingScene. "That's the only thing that sets him apart. He wants to hold one hand, he wants to elbow. I didn't get a deep gash from a punch. I got a deep gash from a headbutt. Low blows."

Mayweather, who escaped with a majority decision win in their first fight, vowed to score a more convincing win in the rematch. He said that he will be more prepared on Sept. 13, saying in jest that he will train like he is preparing for a showdown against a mixed martial artist.

"This camp is going to be totally different," Mayweather said. "I'm going to let my body rest a lot more and I'm going to do a lot more physical training for this fight. Because it's safe to say I'm not fighting a boxer, I'm fighting an MMA fighter."

Maidana, on the other hand, vowed not to change his style for the upcoming rematch, saying that he sees nothing wrong with his rugged technique, which put Mayweather into a lot of trouble in their first fight.

The 30-year-old Argentine then played down Mayweather's accusation, denying that he is a dirty fighter. He also took a swipe at the reigning pound-for-pound king, whom he called the "king of elbows."

"Without a doubt we are going to prove who won the first fight with this fight; with this rematch. I fight dirty? He's the king of the elbows," Maidana said. "The rematch is a big deal in Argentina. The entire country watched the first fight. There's going to be no exceptions in this one. Everybody is going to watch."