Washington, Aug 7 (IANS): American boxer Floyd Mayweather has defended his decision in picking countryman Andre Berto as his opponent saying the latter is "very exciting".

The 38-year-old will face Berto in Las Vegas September 12 in what could be his last boxing match but has a chance to extend his winning run to 49 encounters.

Berto, 31, a former world champion, was a surprise choice given his fall in boxing's pecking order in recent years.

"I chose Berto because he's very exciting," Mayweather was quoted as saying by bbc.co.uk on Thursday.

The match will be the last of a six-fight deal with broadcaster Showtime and thus could be Mayweather’s final time inside the ring.

Critics are accusing Mayweather of picking an easy to beat opponent as Berto has lost three of his last six games but the former believes the 31-year-old will give his 100 percent and push him to the limit.

"Berto is a tough competitor, a former world champion. Every time he goes out he gives it 100 percent," said Mayweather.

"He's been given backlash. I've been given backlash. But Andre Berto is going to push Floyd Mayweather to the limit."

Berto's trainer Virgil Hunter also defended Mayweather's selection, saying: "When you look at that weight division, only one stands out, the rest is opinions. Andre Bento is deserving of this opportunity."

However, Berto went onto say that ideally he would have wanted the fight a few years back.

"We should probably have had this fight a few years back but everything happens for a reason and the time is now."