Floyd Mayweather says his next opponent will be decided within a week. But one thing's for sure: it's not Manny Pacquiao.

Mayweather, who arrived in South Africa on Wednesday, named Britain's Amir Khan and Argentina's Marcos Maidana as contenders for his next bout in Las Vegas on May 3 but said: "We don't know. We will know within the next seven days.'"

The undefeated Mayweather, now 45-0 after dominating Canelo Alvarez for a unanimous decision in September, also passed off eight-division champion Pacquiao's renewed attempts at making their mega fight happen as "desperation" because of the Filipino's unpaid tax issues.