Glasgow Rangers midfielder Steven Naismith will miss the rest of the season after damaging his anterior cruciate ligament during Saturday's victory over Aberdeen.
It is the second time that the Scotland international has suffered the injury, having missed a number of months' worth of action in 2008.
Gers manager Ally McCoist has described the injury as "devastating" but has backed the 25-year-old to bounce back.
"This is devastating news for Steven and our thoughts are with him," McCoist told the club's official website. "He was in the form of his life and it is a huge blow for him and the club that he is out for the rest of the season.
"He will get the best treatment possible in the weeks and months ahead and everyone at Rangers will support him during his rehabilitation period.
"Naisy has recovered from a serious knee injury before and he will come back again. He is a fighter and a popular member of the squad and we will all work hard to win games for him while he is out."
Naismith has scored nine goals in 11 outings this season.