With the start of the new campaign just around the corner, Scholes is confident United have found the right man to guide them back into the Champions League positions.
However, he does not think they can sustain a title challenge as they lack quality in midfield, despite the signing of Ander Herrera from Athletic Bilbao.
"I find it hard to see them as Premier League title contenders this season," he said in his column for the Independent.
"The chief reason I see little prospect of United winning the title is that they have not signed enough players in this window.
"United needed to buy a top-level midfielder, of which there were very few available this summer. Just two, in fact. And Cesc Fabregas and Toni Kroos have already made their moves (to Chelsea and Real Madrid respectively)."
However, following last season's disappointing seventh-place finish under David Moyes, Scholes has plenty of faith in Van Gaal - a man he sees as very much in the same mould as Sir Alex Ferguson.
The former England midfielder added: "Louis van Gaal has the respect of the players. He got it as soon as he arrived. This is a man who has managed some huge clubs: Ajax, Barcelona, Bayern Munich and he has just taken the Netherlands to third place in a World Cup finals.
"He is a man with presence. He looks a bit of a scary man. Good. Sir Alex Ferguson was a scary man too, at times, and it is possible to push players into performances. From what I've seen in pre-season, he looks a bit mad. He's a bit like a mad genius - he looks a bit crazy."
- Sports & Recreation
- Premier League
- Ander Herrera