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 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 (Wednesday).
"It is likely that Steve will be unavailable for selection for a period of around 12 weeks."
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.
Source: PA
