The Dutchman believes that his side can take advantage of City's recent slump and walk away from the clash with all three points.
"I am not jealous of the squad of Manchester City," Van Gaal told reporters. "I am proud of my players and that is the most important thing and when we play like a team then we have a big chance to win.
"We have played very well against West Brom and we played a draw against Chelsea, nobody expected that result but for me it was not enough and maybe the result against Manchester City shall give us that boost.
"It is not the greatest moment of Manchester City, what we have seen of Manchester City in the last matches was not so good. We have a good feeling about this match, our spirit is unbelievable. I think we shall grow and develop ourselves. We need a good result and it could be against Man City."
Meanwhile, City manager Pellegrini has insisted that United are no better than they were last season.