Newcastle United boss Sam Allardyce insists he won't force Michael Owen to play if he needs surgery.

In a development which will set the alarm bells ringing for national boss Steve McClaren, the 27-year-old striker asked to come off six minutes into the second half in Newcastle's 3-1 Barclays Premier League victory over West Ham.

Owen will see a specialist on Monday as the Magpies try to get to the bottom of a problem which could also have major implications for England ahead of next month's Euro 2008 qualifiers against Estonia and Russia.

Allardyce, who ruled the striker out of Tuesday night's Carling Cup clash with Arsenal, said: "We will know better on Monday. It is still a groin problem which we will have to look into a little deeper because it has become persistent.

"We will make a decision from there. We will probably scan it again, have another specialist opinion and then see where we go from there. But he is definitely out for Tuesday.

"I am worried that he asked to come off today because he felt it, whereas it was me who took him off against Derby, so since then, even though the scan was clear, there's a persistent area which is causing him a problem.

"We need to look deeper into that."

If surgery is required, Allardyce insisted that the club would waste no time.

Asked when any operation would be done, he said: "Straight away, if that's the case. We will look after Michael Owen's interests more than anybody else's.

"He is our most expensive asset, so we must not go on any longer than we need to, we must address the injury straight away."