The 25-year old is set to miss the remainder of the season after suffering cruciate ligament damage in his right knee against Aberdeen on Saturday but Whittaker has seen him come through adversity before when he had a similar injury to his left knee which sidelined him for eight months in 2008.
Whittaker admits it is a devastating blow for Rangers but insists Naismith is the type of person to return stronger than he was before the mishap.
"Without doubt we're all devastated for him. It's a big disappointment for the team and for him because he has been fantastic," he said.
"Already this season he has scored umpteen goals so there's no doubt we are going to miss him.
"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."