Newcastle United striker Michael Owen needs a hernia operation.

The Independent says Newcastle manager Sam Allardyce has insisted that substituting Owen after 55 minutes of Monday's 1-0 defeat to Derby County was just "precautionary" - however, his problems are not expected to just go away. Owen may yet play in Sunday's game against West Ham but he will require treatment at some point.

Owen is still a doubt for England's two crucial Euro 2008 qualifiers against Estonia on 13 October and Russia in Moscow four days' later. The question remains how long he can continue to play with the injury without undergoing the fairly simple procedure that alleviates the hernia problem.

Current medical techniques mean that hernia sufferers can - in the best case scenario - return to action within three weeks of the operation. However, in the meantime the condition can be alleviated with anti-inflammatory drugs. The usual advice is that at some point the hernia has to be dealt with through surgery.