Björn van der Doelen says he can easily tell the state of mind of his former PSV teammate and the new Manchester United interim coach Ruud van Nistelrooy. “Sometimes I see the old Ruud on the sidelines,” says the midfielder, who played for PSV between 1994 and 2001. “His chin goes up. I know then that he doesn’t like it at all, he’s boiling inside and he’d rather run on to the pitch.

“When he was a player, he would get angry for a while when his chin went up. Now that he’s older, he seems calmer. Now that chin quickly goes down again.”

Will we see the chin go up as soon as Wednesday when Van Nistelrooy takes charge of his first United game, against Leicester, in the Carabao Cup? It is not impossible as the temper that made him so successful as a player still remains since his transition to the dugout.

His goals for United – there were 150 of them in 219 games – between 2001 and 2006 will make it easier for him in the short run, but it will count for nothing in the long term as another former striker, Ole Gunnar Solskjær, found out.

Van Nistelrooy is an incredibly determined person who has been seen throughout his career as a bit of a predator who cared only about scoring goals and winning trophies. If that required a bit of a fight along the way, then so be it. Van Nistelrooy’s time at United ended after he swore at Alex Ferguson when he wasn’t brought on in a game, as the manager revealed in his autobiography. Van Nistelrooy apologised years later for his outburst.

Not many fiery former strikers grow into top coaches, but do not confuse the player with the coach. Van der Doelen says: “Ruud thrived under pressure. He started playing better in hostile atmospheres. Outside of that he was good with everyone and liked to joke. A great, amiable social guy. I think he is closer to himself now than he was as a player.”

Another former teammate, Ronald Waterreus, says life as a coach is better for Van Nistelrooy. “This suit fits him like a glove. I didn’t see that happening [when he was a player], but it is a relief to talk to him now about the profession of coaching.”

Van Nistelrooy has served one year as a coach in the Netherlands, at PSV during the 2022-2023 season. He resigned just before the last match because he no longer felt supported by the management. He won the Dutch Super Cup, the KNVB Cup and reached the knockout phase of the Europa League. Under his reign, players such as Cody Gakpo, Xavi Simons, Noni Madueke and Jordan Teze became better. He persuaded Luuk de Jong to return to PSV from Barcelona.

Under his successor, Peter Bosz, PSV won the league, reached the last 16 of the Champions League and broke numerous records. Bosz made it quite clear that the foundation to perform so well was already there and that it had been laid down by Van Nistelrooy, something that was appreciated.

The resignation of Van Nistelrooy in May 2023 came as a big surprise to many, even to the director Marcel Brands, who had persuaded him to take the job after he initially said no. At the time he was coach of Jong PSV and felt it was too early to manage the first team.

In December, Van Nistelrooy opened up about his resignation to de Volkskrant. “It felt powerful, that I had the courage to stay close to myself,” he said.

“It made sense to me. Sometimes things are clear enough. Then you continue, with pride, because you stand for certain values, because I was able to help the club further. But there was sadness too because I am no longer the coach of PSV. That sadness remains underneath.

“When the limit is reached, it stops for me. Things happened and that affected me. But now that everything has settled down and I have had time, I know I just want to keep helping young players, that is the essence of it all.”

A cornerstone of Van Nistelrooy is to stay positive, something he learned from another former PSV coach, Bobby Robson. Van Nistelrooy says: “He could explain everything in simplicity and said: ‘Boys, in the media you speak about yourself or positively about somebody else.’ Period.”

While he was managed by many great coaches he names the Englishman (“a gentleman”) as his greatest inspiration. He has also studied closely the master tactician Marcelo Bielsa and team builder Diego Simeone. He is keen to be a mix of them, although most of all, he wants to be himself.

He says he has learned from, among other things, his argument with Ferguson as well as that with Marco van Basten in the Dutch national team during his playing days. “In those moments I let my emotions get too high. It is important you learn to deal with that feeling sooner [so that it doesn’t linger]. There was no emotional outburst when I left PSV. At 47 years, you are too old for that.”

Succeeding, according to Van Nistelrooy, is a case of sticking to his core values: be humble, involved and reliable. “Those frameworks, that is me,” he says. “It is about basic attitudes. People always see me as that striker from Manchester United and Real Madrid, but I am not only that.”

He has also learned that he knows how to work with a group of players, make them better, inspire and motivate them. He wants to work somewhere where they share his philosophy, somewhere that makes his heart beat faster. “Having the ball, being creative, quickly to the goal, but also knowing how to survive,” he says. “Can we be Atlético Madrid for 15 minutes? Because I only want to win.”

Finally, and perhaps most importantly, he has learned how to take people with him when he goes in a certain direction with a team. “Otherwise you will lose them,” he says.

His spell in charge of United may be short – this time at least – but one thing is for certain: he will give it everything he can to succeed.