The former Red Devils striker has taken interim charge at Old Trafford following the sacking of Erik ten Hag and revealed that he would be willing to remain on the coaching staff under the new boss - with Sporting Lisbon's Ruben Amorim tipped to take the post.
Van Nistelrooy - who led United to a 5-2 win over Leicester in the Carabao Cup on Wednesday (30.10.24) - said: "Of course – I came here as an assistant to help the club.
"Now in this role, I’m helping as long as needed. In the future in any capacity, I’m here to help the club further to build towards the future that’s what I’m here for."
Van Nistelrooy turned down management jobs to return to United as an assistant in the summer and will do anything possible to help his old club going forward.
He said: "I’m here to help and serve and give my everything for the club in any capacity with so many people here around me that want the best for the club and that will never change."
Van Nistelrooy had written in his programme notes before the game that United could be "unstoppable" if everyone at the club "pulled together".
He said: "Even on an interim basis, it is a great honour to manage the club I love for however long I am asked to do so.
"When I returned in the summer as Erik’s assistant, it was because I believe that Manchester United can climb back to the levels that I knew here as a player.
"I still have that belief, but it will take time and a lot of hard work.
"We’ve seen the squad’s potential at times this season, but clearly not often enough."