Manchester United defender Phil Jones faces up to eight weeks on the sidelines with a knee injury.
Jones suffered the injury in training earlier this week and was sent for a scan that confirmed he requires an extensive period of rehabilitation.
"Phil Jones has had surgery on a knee meniscus tear sustained in training that will require six to eight weeks' rehabilitation," a statement issued by the club read.
It is desperate news for the 20-year-old, who is yet to make an appearance this season.
After an extensive break following Euro 2012, Jones suffered a back injury that prevented him from playing any part in the preseason.
He missed United's opening three Barclays Premier League games and the start of England's World Cup qualifying campaign, but Jones' return to training was supposed to be the prelude to his comeback.
Instead, Jones is sidelined until November.
It means he will miss England's next two qualifiers against San Marino and Poland next month.
More importantly for United though, he is ruled out of a succession of key league fixtures, including matches against Liverpool, Chelsea and Arsenal.
In addition, he will miss at least the Red Devils' opening three Champions League group matches.
Even when he has recovered, Jones' lack of match fitness may prove a significant problem in regaining the form which at one stage saw him compared to Duncan Edwards during an exceptionally encouraging debut campaign following his big-money move from Blackburn in 2011.