Newcastle revealed tonight they expect Steve Harper to be out of action for around 12 weeks after undergoing shoulder surgery.
The 35-year-old sustained the injury in Saturday's 1-0 Barclays Premier League victory at Everton in a first-half incident involving Toffees striker Jermaine Beckford.
A Newcastle spokesman tonight said: "Following a shoulder ligament injury sustained in United's game against Everton last Saturday, Steve Harper has undergone a successful operation which took place yesterday. It is likely that Steve will be unavailable for selection for a period of around 12 weeks."
Beckford was booked for the challenge by referee Andre Marriner. Although the tackle was not a particularly bad one, it ended the involvement in the game of Harper, who landed heavily on his left shoulder and immediately looked in distress before being carried from the field on a stretcher.
It means the player is unlikely to figure for Newcastle's first team again until the middle of December - and is likely to mean an extended run in the side for Tim Krul.
Krul replaced Harper at Goodison Park and was also in goal for last night's 4-3 Carling Cup third round success over Chelsea at Stamford Bridge.