WBA and IBF light-welterweight champion Amir Khan has questioned Floyd Mayweather Jr's conditions for a possible future fight.

Mayweather Jr had said that the Brit must fight his protege Jessie Vargas before being given a crack at the American.

"Never heard of Jessie Vargas until Floyd Mayweather mentioned that I have to fight him," Khan told boxingscene.com.

"He looks good, yes, but only has 16 fights. He's a prospect and I'm a unified world champion. If Jessie Vargas fights and gets past Marcos Maidana, then I'll fight him. Like Floyd said, you have to earn it."

The 24-year-old will fight either Lamont Peterson or Paul McCloskey at the end of the year for his last contest in the light-welterweight division.