He essentially is the ceo/coo of Mayweather Promotions. He also serves as Mayweather's strength and conditioning coach.
He's like his personal assistant and handles the business aspect of Mayweather Promotions. Floyd's entourage, the core, is basically family. From the cutman to Ellerbe to Rog/Sr., Floyd's used the same crew throughout his life (amateurs/pros). He may fellate Floyd from time to time too