Boxing legend Floyd Mayweather has backed Ronda Rousey to "bounce back" from her brutal 48-second loss during her Ultimate Fighting Championship (UFC) women's bantamweight title match against Amanda Nunes on 30 December.

The California-born former UFC women's bantamweight champion was returning to the octagon for the first time in over 13 months following her TKO loss against Holly Holm in November 2015. It was her second consecutive loss — they are the only two during her professional MMA career that began in 2011.

Rousey's back-to-back losses have raised questions about her future in the sport, but talks about her being overrated were rejected by MMA fighter Jon Jones. The Boxing legend pinpointed her lengthy time off as one of the main reasons for her shock loss, but is confident the American fighter has a lot left in her locker to make a successful comeback.

The 29-year-old has been the face of women's MMA for many years, and UFC president Dana White has reaffirmed his support after only her second loss and admitted that without Rousey, women would not be in the UFC.

"I don't want her to think this is the end of the world," Mayweather said, as quoted by Fox Sports. "She's hearing it from the best. She'll be okay. Ronda Rousey, hold your head up. You're still a true champion in our eyes. You made women's MMA huge, so stay focused, go back to the drawing board and do what you gotta do."

"I think her losing had a lot to do with time off. She maybe should have competed against another female MMA fighter that wasn't as active as the female that she faced. I think the female that she faced was rugged and tough. The girl Ronda Rousey faced was a tough competitor. She was the better woman that night. But Ronda Rousey has a lot left.

"I want Ronda Rousey to hold your head up, stay focused and keep believing. A true champion can bounce back — you'll be okay. Everything will be okay," the boxing legend added.