O'Leary's word of warning on Vieira

David O'Leary, the Leeds United manager, has condemned the behaviour of the Arsenal midfielder Patrick Vieira and claimed that his old club have not heard the end of the Frenchman's transfer request.

Arsène Wenger, the Arsenal manager, has hinted that Vieira has been persuaded to stay with the North London giants after publicly lambasting their new arrivals and claiming he wanted to move on.

Wenger insists Vieira never said he wanted to leave Arsenal and the transfer talk has been whipped up by his agent.

However, O'Leary, who lost his leading striker Jimmy Floyd Hasselbaink in similar circumstances two years ago, feels player power has taken control of the game and if Vieira really wants to leave, he will.

"I wouldn't wish Patrick Vieira's behaviour this summer on any manager," the Irishman said. "Arsenal are confidently insisting Patrick will honour his contract and that the matter is closed. I hope they are right, but in my experience these things can often rumble on under the surface.

"Already Vieira and his agent have undermined his manager and his club. It must have cast a huge cloud over Arsenal at a time when you want to be looking forward to the new season with confidence and optimism." O'Leary, who has yet to add to his squad this summer, remains a huge admirer of Vieira's on-field talents.

"Arsenal are making all the right noises by insisting Vieira must stay and they are right to do so. But that's easier said than done.

"They said they wouldn't sell Nicolas Anelka when they found themselves in the same boat with him a couple of years ago. In the end he went for £23m. When one of your best players tells you he wants to go, it's a depressing situation for any manager.

"I've been there, done that and got the T-shirt – and it's got Jimmy Floyd Hasselbaink's name plastered across it."