The American's father has admitted that the 35-year-old is starting to show signs of a possible decline but insists that he is still more popular than his rival Manny Pacquiao.
Mayweather Snr told ON The Ropes: "It's been proven already that my son can sell more tickets than Pacquiao! It's been proven that on a couple of different occasions that my son can sell more tickets than Pacquiao.
"Age might be catching up with him [Mayweather Jnr] now. I'm pretty sure it's catching up with him. He's not Superman.
"Even though he keeps his body and stuff in good shape, you know I'm pretty sure that's going to have a big thing to do with it too."
Mayweather Jnr revealed this week that a potential fight with Pacquiao is unlikely to take place this year.