He feels Yorke may be more vulnerable than Andy Cole, Teddy Sheringham or Ole Gunnar Solskjaer because of his poor form this season.

"You would have to think how are they going to keep five strikers happy?" he said.

"There are only going to be two or three happy most of the time.

"Solskjaer has already gone on record saying he wants to stay at United and he seems to have accepted the situation.

"He isn't going to be a problem and I would think Teddy Sheringham would sign his contract.

"Sheringham may be concerned about van Nistelrooy's arrival, but, he's had a fantastic season. He's played very well and he's the Footballer of the Year.

"If anyone could be vulnerable it could be Yorke and most of the speculation has surrounded him.

"His form has been in and out this season, although there have been mitigating circumstances and he's been injured while the travelling with Trinidad and Tobago has not helped."

Stapleton, though, does not believe it is certain that United will automatically try to offload a striker to make way for van Nistelrooy.

"I know that Martin Edwards said last year before van Nistelrooy's first move broke down that one striker would have to go, but I would have thought if the manager wanted to keep five strikers that would not be a problem," he said.

"There have been times this season when United have been stretched up front even with the squad they have got.

"I'm thinking of Christmas time when Solskjaer was the only striker they had.

"So maybe five is the right number to have nowadays."