The Dutchman adds that is he yet to fully assess his new squad of players and won’t be rushed into making changes.
For the opening two matches of their pre-season north American Tour, van Gaal says he opted for a system best suited to the players at his disposal – which is why wingbacks played a prominent role against LA Galaxy and Roma.
Talking about his squad, van Gaal said: “I don’t buy players for the sake of it. I buy players to improve my selection.
“First, I must see what I need in all the positions from the system we shall play and, at this moment, I don’t know for sure.”
Many have questioned how Wayne Rooney, Juan Mata and Robin van Persie can all fit into the same United starting XI but van Gaal admits this was one of the main reasons why he employed the formation he did.
He went on: “That’s why I chose this system, I can play them all. But (Javuier) Hernandez can also play in the striker’s position, so can (Danny) Welbeck.
“Rooney can play at No 10 and No 9 and he tells me he can also play at No 11 and No 7, but I prefer him at 9 or 10.
“When you look at the quality of your players you see Rooney, Van Persie, Hernandez, Mata, Welbeck, (Marouane) Fellaini, (Ander) Herrera – a lot of players can play this system.
“So with this system, two strikers can play, the No 10 can play, two midfielders can play, so the specialists become the wingbacks.”
Van Gaal says he feels no pressure taking over at Old Trafford because he has had similar experiences elsewhere.
When asked was it an easy decision to become manager, he explains: “It was not an instant ‘yes’ because I had other offers also. So I had to think about it.
“But I chose ‘yes’ because of the big challenge. I have been at Ajax – the biggest club in the Netherlands – I went to Barcelona – the biggest club in Spain – and then I go to Bayern Munich, also the number one in Germany.
“So when Manchester United came I thought I had to say ‘yes’.”
As for trying to emulate Sir Alex Ferguson, he says: “I had to follow Bobby Robson at Barcelona and that year he won three titles. And I had to succeed him.
“I highly respect Sir Alex because there is not another trainer or manager who has won so many titles.
“I have won a lot of titles but he has won so many with one club and that is fantastic. So when you compare Sir Alex with me I am very proud.”
And asked how he will deal with the mind games employed by other managers in the Premier League – namely Chelsea boss Jose Mourinho – van Gaal explained: "I don't think I will fall out with him. He is my friend.
"I don't think I will fall out with all the other managers. I have full respect for all of my colleagues.”