Steven Whittaker admits the Rangers squad have been left 'devastated' by the news that Steven Naismith will not play again this season.
The Scotland international saw his campaign brought to an abrupt halt on Saturday when he suffered anterior cruciate ligament damage in a 2-1 victory over Aberdeen.
Scans have confirmed Rangers' worst fears and it is expected that Naismith will be missing for around nine months.
It is not the first time the 25-year-old has been dealt such a blow, with a similar injury striking his left knee in 2008 - putting him out for eight months.
Whittaker admits the loss of Naismith will be keenly felt, with the midfielder having already netted nine times this season.
He said: "Without doubt we're all devastated for him. It's a big disappointment for the team and for him because he has been fantastic.
"Already this season he has scored umpteen goals so there's no doubt we are going to miss him.
"His hand went straight in the air as he crumpled to the ground and it was pretty clear then that it looked like it would be serious.
"You never know until you get the scan done but we thought it would be serious and it has turned out that way.
"He's a determined character though and we all know what he's like at this club. He has a great personality and hopefully he'll back to his best sooner rather than later.
"It's never nice getting one of these serious knee injuries but in the modern game a lot of players are coming back from these types of injuries whereas in the past it might have been career threatening.
"He's been there before so he knows what to expect and I'm sure he'll be back stronger than ever."
Naismith's absence will open the door to somebody else in Ally McCoist's squad, but Whittaker admits that whoever comes in will have some sizeable boots to fill.
He told the club's official website: "It's obviously down to the manager's vision who he sees as coming in and grasping the opportunity because there is a gap there to be filled.
"Whoever comes in I'm sure will do well but Naisy is a terrific player and brings great energy to the side and that will be missed."