Floyd Mayweather Jr has ruled out any prospect of suffering the first defeat of his 43-fight career when he comes up against Robert Guerrero next month.

The 36-year-old has not fought since beating Miguel Cotto for the WBC middleweight title a year ago, in which time he has served a 90-day jail term for domestic abuse.

However, he does not believe that the time out of the ring will affect him when he goes toe to toe with Guerrero at the MGM Grand on May 4.

"No-one has a blueprint on how to beat Floyd Mayweather Jr," Sky Sports News quotes the American as saying. "All 43 opponents had a gameplan, all 43 opponents came up short. No-one has found a way to break the Mayweather code.

"We want a fighter like Robert Guerrero that is confident and that believes in his skills so I can be pushed to the limit, that's what it's about.

"I don't think the layoff will hurt me. I've faced every style, so it's not hard for me to make adjustments."

Guerrero brings a 31-1-1 record, with the only defeat of his career coming in a featherweight contest against Gamaliel Diaz in 2005.