Chelsea centre back Levi Colwill suffered an anterior cruciate ligament ACL injury in training, the Premier League club said late on Thursday, with the 22-year-old expected to miss much of the new season.
The England international underwent successful surgery on the injury, Chelsea added.
It typically takes some six to nine months for a player to recover from an ACL injury and return to action.
The 22-year-old had reported back to Cobham for pre-season at the start of this week, before unfortunately sustaining the injury in training, Chelsea said in a statement.
Medical assessments confirmed surgery would be the required course of action.
