As a coach, Van Nistelrooy has retained his obsession with perfection.
The Dutchman became a coach in the PSV academy after retiring as a player at Malaga in 2013 and was promoted to first-team manager in 2022.
When he resigned in 2023, after winning the Dutch Cup and finishing second in the Eredivisie in his only season in charge, he had no shortage of offers.
Instead he took a year out to learn from other coaches around the world at clubs such as Spanish giants Real Madrid and Argentine powerhouses Boca Juniors and River Plate.
“He’s not a proud man in that way, he’s not arrogant. He wanted to bounce his own ideas off others,” Marcel van der Kraan, sports editor of Dutch newspaper De Telegraaf told BBC Sport.
“On his dream football trip, he went to all the big games. He spoke to Martin Demichelis, the River Plate manager, for hours and hours about coaching.
“He also went to experience the football culture. He told me he walked through La Boca in Buenos Aires and saw ‘The eternity of Maradona’ painted on the walls in tribute to the Argentina legend, who died in 2020. He said: ‘You need to win the culture of an area.’
“At Man Utd, it’s probably more vital than at any other club in England that you know the culture of the club, of the area, and Ruud does.”