• ‘I’m not reacting to that kind of stuff,’ he says of Chelsea coach • Van Gaal warns United might struggle for first three months

Louis van Gaal insists he will not be provoked into a war of words by José Mourinho after the Chelsea manager fired the first shots of the season by criticising Luke Shaw’s wage demands.

The Portuguese had claimed the left-back could have joined Chelsea but his reported salary of £100,000 a week would have “killed” the club. Mourinho often tries to engage opposing managers in mind games, with Arsenal’s Arsène Wenger and Manchester City’s Manuel Pellegrini among his targets last season.

Van Gaal, who made Mourinho his assistant at Barcelona in 1997 after inheriting him from Bobby Robson, who employed him as a translator, is refusing to let his new rival get under his skin, however, before United and Chelsea meet at Old Trafford on 26 October. “He shall not do that with me,” the Dutchman said. “I play against Chelsea. And not against José Mourinho. My team and his team are playing against each other.”

Asked about Mourinho’s comments regarding Shaw, Van Gaal, whose United side have won their opening two games on the summer tour of the US, said: “No. I’m not reacting to that kind of stuff.”

Van Gaal has described United as “broken” following their seventh-place finish last season, and he believes it may be three months before the team start to be successful. “Every club where I have been, I have struggled for the first three months. After that they know what I want: how I am as a human being and also a manager, because I am very direct,” he said. “I say things as they are, so you have to adapt to that way of coaching.

“It’s not so easy. And also the way I train and coach is in the [players’] brains and not the legs. You have seen my exercises with all the tactical [approaches] and without the tactical [approaches].

“I am not for running for its own sake and I am for running with the ball, but they like that, of course. But the most important thing is they have to know why we do things and when they do, the football player is not playing intuitively.

“A lot of players are playing intuitively and I want them to think and know why they do something. That’s a process that is difficult at first and in the first three months. It takes time.

“When we survive the first three months, it will be the same as for me as at Bayern [Munich]. After the first three months we were sixth or seventh, and we were third in the Champions League group. We had to win at Juventus and we won that game [4-1 in 2009] and that was the turning point.”

The Dutchman has signed a three-year contract but his vision for United is to build a team that will have long-standing success. Van Gaal points to the legacy of his tenures at Barça and Bayern.

“That is always my philosophy. I’m not a coach who thinks short term. I am a coach who thinks always in the long term,” he said. “The way you see Barcelona are still playing with six players from my time because I gave a lot of chances to the youth players – the structure and the culture of the club is Xavi, Iniesta, Puyol, Valdés and Motta – I also gave [Motta] his debut and he is playing in Paris Saint-Germain, not a little club.

“At Bayern Munich it was the same. You can see that in Müller, Alaba, Kroos, that kind of player. So I am always for the long term, not the short term. When I buy, I buy players for the long term, not the short term, because I do respect the club a lot and also the other clubs. You can see this at Ajax. I had the youngest team to win the Champions League with 17-, 18-, 19-year-old players [in 1995].”

Van Gaal also talked of why he likes to promote youth players from within the set-up. “The argument for that is when you use youth players of the club they know the culture and they want to defend that culture and wear that culture and transfer that culture,” the 62-year-old added.

“When you buy a player from outside you have to wait and see and not every player will fulfil your expectation. It is much more difficult, also for the player.”