The Dutchman has decided to forgo the opportunity of becoming a head coach once again, opting instead to join manager Erik ten Hag's coaching staff.
"This is 100 percent the right decision. I felt a strong feeling that I want to help build United little by little to get back to where we feel and know where the club should be," Van Nistelrooy told TNT Sports.
"I was on a coaching track. I coached PSV, it was an incredible experience. I was in talks with clubs and I love it (being a head coach). I had my staff ready and then I got a phone call. I never even saw this as a possibility.
"Erik (ten Hag) called me and talked it through. I began to love the idea."