Floyd Mayweather trains with a wad of cash in his hand as he hit a punch bag

Floyd Mayweather holds a huge wad of cash while training with a punch bag ahead of his upcoming fight with Andre Berto in Las Vegas on Saturday September 12.

The 38-year-old boxing superstar was preparing normally before deciding: ''I need motivation, let me hold it while I'm training.'' Mayweather then grabbed the money and continued to throw punches with his left hand.

Mayweather has promised to bow out after his 49th fight at the MGM Grand in Las Vegas on September 12.