Louis van Gaal: 'I know that Manchester United is the biggest club in the world - not Real Madrid'

United boss also admits that this job will be his last in football

Louis van Gaal believes that he is in charge of the biggest club in the world.

The Manchester United manager, who also admitted that he will retire once he ends his reign at Old Trafford, said he realised the fact during the club's pre-season tour of the US, when he saw more United shirts than any other despite Real Madrid taking place in the same tour.

"We were in the USA and we played against Real Madrid, Liverpool, Roma, Inter Milan and LA Galaxy, five matches in three weeks, 300,000 fans and I think 280,000 of them in a red shirt," he says in a lengthy interview with the Daily Telegraph.

"I know that Manchester United is the biggest club of the world.

"[Are they bigger than Real Madrid?] Yes. In terms of global appeal, not history.

"I made a trip with my wife through the world when I had a sabbatical year and I was in China and Hong Kong and such football madness in those countries! They recognise me everywhere. Unbelievable. And they know Manchester United much more than the manager."

Van Gaal, now 63, said that despite his stubborn and cold reputation he is "the most flexible manager you can imagine".

"When the players are coming with good arguments, I change my opinion.

"Yes [I would change tactics]. They need to have very good arguments. It is not so easy to convince me - that’s true. But when you convince me I change my opinion."

Manchester United were excellent against Spurs last weekend (GETTY IMAGES)

With United drawing heavy criticism this season for their style of play, and some of the formations - especially three or five at the back - Van Gaal says the formation he played against Spurs is his "preferred" way of playing.

"I ask also the players which system they want to play. And then I ask individual players: 'What’s your favourite position?' First they don’t want to answer but now they are more open, and they answer.

"No [they don't all ask for 4-4-2]. The fans are shouting it. I have played it but that was to do with accidental circumstances.

"The system we play now is the system that I prefer, that I have played everywhere. Yesterday [Spurs on Sunday] is my preferred system. When it is needed, then I play with five at the back. Yesterday was 4-3-3 when we had the ball. For example, Juan [Mata] more inside and [Ashley] Young outside. When we defend it was more 4-1-4-1 yesterday. Next game is different."

With 24 years of management and seven league titles in five countries under his belt, the Dutchman said this would be his last stop.

"I am also old. This is my last job. For sure. I have to pay attention to my kids, my grandchildren but also to my wife. They deserve it. Now I cannot pay that attention. I was not at the birthday of my grandson for example. I don’t like it."