There seem to be alot of good muslim players around but I have not heard much talk about this issue. Maybe many of them dont fast but maybe we are over exaggerating the impact it has.
players such as: Ribery, Van Persie, Kanoute, Muntari, M. Diarra, Tuncay, Anelka, Nihat other turk players and players from muslim countries ... there are so many yet you dont hear much talk of Ramadan being a problem.