The 36-year-old has been tipped to take on Khan after the British boxer signed a contract in December for a showdown that could potentially take place in Las Vegas this May.
However, Mayweather has asked his fans on Twitter to vote on whether he should face Khan or 30-year-old Argentine Maidana.
Mayweather wrote on the social networking website: "I'm going to let the fans vote. Tell me who I should fight next. Khan or Maidana?"
Khan won his most recent fight against Julio Diaz in April.