The Sun:
Former Gunners skipper Vieira, who quit Highbury for Juventus last summer, made the claims in his recent autobiography.
The Dutchman said: "The incidents during the United-Arsenal matches have clearly affected him as he’s obviously still very frustrated. But he’s entitled to say what he thinks of me.
"It was all about the promotion for his book. Newspapers read that and it was the juiciest bit, so they reported it.
"People have asked me if I’ll sue over it, which is stupid. Why should I waste my energy on something so trivial?
"I don’t understand why Patrick Vieira’s still so stressed out about things that have gone, particularly as he’s not even playing in England. The whole issue is immaterial and isn’t worth talking about."
Van Nistelrooy said he may write his own book when he hangs up his boots — but insisted it would not be filled with scandal.
He said: "I haven’t the need or desire to seek revenge or hang dirty washing out to dry."