Ruud van Nistelrooy says the most painful part of his Manchester United exile is missing out on Roy Keane's testimonial at Old Trafford tonight.

The Dutch striker is back in Holland training with Marco van Basten's World Cup squad after being left out of Alex Ferguson's first team plans since the game with Charlton at the weekend.

As one of the few senior players who stood up for Keane over the never-to-be-aired MUTV rant which led to the Corkman's abrupt departure from Old Trafford in November, Van Nistelrooy was looking forward to meeting up with his old team-mate again.

Instead, the 29-year-old is now back home, knowing his United future is non-existent, having phoned Keane to explain why he could not be there for tonight's encounter with Celtic.

"It is painful because I wanted to be there to respect Roy but I have not been allowed to," Van Nistelrooy told Sky Sports. "That is the most painful thing of all. I have spoken to Roy and he is totally fine about it."

Van Nistelrooy is expected to be part of Van Basten's World Cup squad, which is due to be announced on May 15. And, given the severity of his falling-out with Ferguson, it appears he will be using the competition as a shop window to display his talents.

It is believed Ferguson has now spoken to United chief executive David Gill about the situation, as the Scot promised in the aftermath of Sunday's win over Charlton. PA