Leading Rangers scorer Steven Naismith could miss the rest of the season after suffering cruciate ligament damage.
The Scotland international was stretchered off during the Glasgow side's 2-1 victory over Aberdeen on Saturday.
Naismith has been for a scan on the injury but the Rangers medical staff are not expected to know the full extent of the damage until Thursday.
However, they fear that the forward may have suffered a repeat of the injury which kept him sidelined for the majority of 2008.
"The fear is that Naismith has suffered damage to his anterior cruciate ligament in his right knee and if that is the case he will be unlikely to feature again this season," read a statement on the official website.
The former Kilmarnock player has scored nine league goals for Ally McCoist's side this season.