Fellaini has come in for criticism from Man United supporters recently as the side often resort to long-ball tactics with him in the starting XI.
However, van Gaal believes the Belgian has been making a positive impact on games this term.
“I cannot say if Fellaini plays tomorrow because then I give away part of my line-up and I don’t want to do that but Fellaini has his way of playing and he can give us a lot of qualities and has contributed in a lot of games in a very good way,” van Gaal said.
United, under Sir Alex Ferguson, built a reputation of playing in a certain way.
Fast wingers and exciting forward play characterised what was a daunting style of play for opponents to face and it won United a number of trophies.
The frustration for United fans is that Fellaini typifies what their side have become: slow, laborious and too calculated in their approach. All supporters are asking for is to get off their seats and Fellaini rarely provides those moments in games.