Leicester's Patrick Kisnorbo looks set to be sidelined for up to six months after picking up a cruciate ligament injury.
The defender has suffered a partial anterior tear to the ligament and now faces a lengthy period of rehabilitation.
He was forced off on a stretcher during the first-half of the Foxes' 3-1 defeat at home to Sheffield Wednesday on Saturday.
A scan has since revealed the full extent of the damage and Kisnorbo will now undergo surgery over the summer in an attempt to rectify the problem.
"It looked innocuous at the time, but those cruciate injuries always do," City manager Ian Holloway told the club's official website.
"We have now got to decide if he will have his surgery over here or in Australia.
"The good thing is he has got the right people around him at the club. Our medical team here have dealt with similar injuries in recent years and they are confident that he will come through it.
"Levi Porter did his cruciate against Chelsea earlier in the season and he is back in training now."