Last season's finalists face off tonight.
"Up until now I haven't seen Inter play in a different manner," Van Gaal said.
"Whoever saw the Final knows very well what happened. It's enough to watch Inter play every week to know they're defensive.
"Even against Cagliari they closed things up without doing anything to attack their opponent.
"You see that a Coach and a club has decided to play this way. I instead would like to offer a more attractive brand of football to the fans.
"It's more difficult to think only about defending yourself. But that's my idea of football.
"We want to win. The holders are always the favourites. In this case that's Inter who also play at home."