Ricky Hatton has defended Floyd Mayweather's decision to face Andre Berto in what the undefeated world champion insists will be the final fight of his illustrious career.

Mayweather is widely expected to equal the legendary Rocky Marciano's 49-0 record at the MGM Grand on Saturday, when he puts his WBC and WBA Super World welterweight titles on the line.

Many observers have criticised Mayweather's decision to face the relatively unheralded Berto, who has lost three of his last six fights and only fought twice since July 2013.

However, Hatton - who lost his own unbeaten record to Mayweather in 2007 - told Omnisport: "I don't think he [Berto] is the force he was a few years ago, but a lot of people are complaining about Floyd's choice of Berto for this fight. I don't think so. How can you have a pop at Floyd for who he's fighting, he beat everyone.

"He's fought Canelo [Saul Alvarez]; he's fought [Miguel] Cotto; he's fought [Shane] Mosley; he's fought me; he's fought [Oscar] De La Hoya, you know what I mean? He's fought [Manny] Pacquiao.

"I don't think you can say that Floyd picks a dodgy opponent because I think that's a disrespect to Andre Berto.

"He's a good fighter and like any fighter will know, once you get a fight everyone's expecting you to win sometimes you can take your foot off the gas and it can all go bangers as they say."

It remains to be seen whether Mayweather will stick to his pledge to hang up his gloves after Saturday's bout, with Hatton among those who believe the 38-year-old will be motivated by the prospect of surpassing Marciano's record.

The build-up to this weekend's fight has been overshadowed by a doping controversy relating to Mayweather's last outing - which saw him claim victory in a much-hyped contest with Pacquiao in May.

Both Mayweather and the United States Anti-Doping Agency (USADA) issued statements denying any wrongdoing had taken place after it emerged the latter retrospectively approved a request from Mayweather to have an intravenous infusion of saline and vitamins administered prior to facing Pacquiao.

The news has prompted speculation over a possible rematch between Pacquiao and Mayweather, which could well appeal if the latter is indeed tempted into a 50th fight.