Leeds manager Neil Warnock was left saddened by the news that Leigh Bromby had to be taken to hospital after suffering a serious injury.
The defender faces a lengthy spell on the sidelines after rupturing a tendon in his right knee after slipping awkwardly midway through the first half during the 1-1 draw at Cardiff City.
Bromby required oxygen as he was carried off on a stretcher and his team-mates were visibly shaken by the horror fall.
Warnock said: "Leigh has ruptured his patellar tendon. He hasn't gone to hospital because he won't save anything now. He will have an operation next week.
"He will be out for a long, long time - I'd be surprised if he is back before Christmas. It could be a year. I'm gutted and disappointed for him because he has just come back in the team and done well.
"He was in agony and required oxygen because he had passed out. But the Cardiff fans were fantastic. They were very supportive straight away and the ref showed he knew what he was doing. I want to say a big thank you to everyone for the way they reacted."