Kilmarnock manager Kenny Shiels has revealed that defender Ryan O'Leary will miss all footballing action for the next six months because of a damaged cruciate ligament.
The 23-year-old suffered the injury during his side's goalless draw with Hearts in the Scottish Premier League on Sunday.
O'Leary got involved in a goalmouth scramble in the first half at Rugby Park and was substituted at the interval.
Shiels has now revealed the extent of the injury one of his key defenders has sustained.
"Alex (McQueen), my physio, sent me the message to say it's a cruciate injury, which is six months," Shiels said. "I really feel for Ryan because he's had a couple of injuries in his career.
"He has worked his way back and psychologically he was really up for this season. Now we have to try to manage his coping strategy and how to deal with this.
"James Dayton will be a big help because he has been through this last season.
"It's a horrible injury for a player because the rehab is so tough - we have the backroom staff to deal with that."
Kilmarnock are currently sixth in the league standings, having collected six points from four matches. They are away at Inverness on Saturday.