Arsenal midfielder Jack Wilshere will be out until at least January after undergoing ankle surgery on Monday.
The Premier League club said the early indications were that the operation to repair a stress fracture in Wilshere's right ankle was a success.
''It is envisaged that Jack's rehabilitation will take a period of four to five months,'' Arsenal said on its website.
The 19-year-old England international sustained the injury in June and hasn't played since it flared up again in a preseason game against the New York Red Bulls.
Not only will Wilshere miss Arsenal's entire Champions League group stage, but also England's last 2012 European Championship qualifier at Montenegro next month and a potential November playoff.
''My ankle is little bit sore, but I'm already looking forward to working hard to get fit and playing again,'' Wilshere said.
Arsenal has had a rocky start to the season in Wilshere's absence, losing three of its six Premier League games to sit 12th in the standings.
