Everton's James Vaughan has undergone another knee operation. The 21-year-old, who has experienced knee problems in the past, returned to Goodison Park this week to have an injury assessed after being on loan at Championship Derby.

Scans have revealed a slight tear in his knee cartilage, although Everton have stressed it is a new injury and not a recurrence of any past problem.

Everton's head physiotherapist, Mick Rathbone, told the club's official website: "James suffered a slight tear in his cartilage while playing for Derby a couple of weeks ago.

"If there is anything positive at all about it, it's that this is a brand new injury - it's not a recurrence of anything he's had before.

"It's a very minor tear and James has been to London this week to have the cartilage trimmed.

"We hope that he won't be out of action for too long."