Kilmarnock captain Manuel Pascali has been ruled out for the rest of the season after suffering a broken fibula in a freak training ground accident.
The Italian sustained the injury while stretching for the ball on Friday ahead of Saturday's home game against Hearts.
Defender Pascali is a major loss for Kilmarnock, who are aiming for a top-six place in the Scottish Premier League and face Celtic in March's League Cup final.
"I am really disappointed for Manuel. It is a really big blow for him and the team," said manager Kenny Shiels.
"He has so much passion to do well, and there was the cup final for him coming up. It wasn't an impact injury, it was while he was stretching for the ball.
"It gives the opportunity for other players to come in and try to stake their place, but I am really gutted.
"We now have to garner some intensive energy to make up for the loss of Manuel."