As the summer of 2006 approached, Ferguson decided to pick Giuseppe Rossi ahead of Van Nistelrooy for the final game of the season against Charlton.
The Dutchman drove away from Old Trafford in disgust and - until Friday's unveiling of a Ferguson statue - had not been back since.
"When he is building new teams he is willing to do things like that," said Van Nistelrooy.
"That is all credit to him. In his mind, the club is the most important thing.
"That is what he always said. It is his most-repeated sentence.
"What he did was fair enough. I didn't find it hard to deal with. I accepted it.
"I moved on to Madrid and had four great years there. He moved the club further onwards. My overall feeling about United is that I had a great five years there and I wanted to come back today to pay respect to the manager because I am very grateful for the chance he gave me.
"Of course, we had our things with the way it ended but he is man who gets the best out of people. He did that with me as well."