Van Gaal said this while speaking with Dutch LGBT newspaper, Gaykrant.
According to him, football “is not a mirror of society”.
Van Gaal, 68, who retired one year ago, however, admitted that he suspected that some players he managed were homosexual.
But he says that sexuality remains such a taboo subject inside dressing rooms and he would never advise a player to come out.
Asked if there are any gay footballers, Van Gaal said: “Yes, but not many.
“The football world is not a mirror of society.”