The Scotland caps became the first players to publicly confirm they would walk out on the newco club and they also blamed new chief executive Charles Green for doing nothing to consult with them until sending an email last Thursday.
Rangers are bracing themselves for the pair being the tip of the iceberg, with Steven Davis, Allan McGregor, Kyle Lafferty, Lee Wallace and Carlos Bocanegra also weighing up whether to exercise their right to object to the transfer of their contracts from oldco Rangers to the newco under TUPE (transfer of undertakings, protection of employment) legislation.
Rhys McCabe and Sone Aluko are also expected to leave. Rangers' pre-season training begins on Thursday and manager Ally McCoist does not know how many players will report for duty.
Naismith pointedly referred to the newco Rangers only as "Sevco" – the name of Green's holding company – at a press conference yesterday and insisted the club was no longer the one he had supported since childhood. Both he and Whittaker now regard themselves as free agents who will attempt to find new clubs, almost certainly in England.
"I am disappointed and angry that Rangers Football Club no longer exists in its original form," said Naismith. "I am angry as a fan. I grew up supporting a club that has been liquidated and a new company, Sevco, has effectively taken its place.
"My loyalty was with Rangers Football Club. That's the team that signed me and that's the team I took a 75% pay cut for. It's effectively a new company now, Sevco, and I'm glad I've made this decision.
"This is a new company called Sevco. I've never met Charles Green or anyone from Sevco. I don't know who the investors are or what league they'll be in. So how can I push forward into a new company that I don't know anything about or any person involved in it? The first I heard from Charles Green was on Thursday through an email. You would think they might have been in contact before then considering the enormity of the situation."
Naismith declined to speculate on whether other big names would follow him out of Rangers, but he said their seemingly inevitable exclusion from the Scottish Premier League next season had been a huge factor for him.
"I feel it would hold me back to go and play in the first division or the third division at this stage in my career. I can't speak for any other player, it is their decision. I came to mine after speaking to my family and representatives. No-one inside the club has influenced my decision."
Whittaker echoed Naismith's view that a drop into the lower leagues would be too damaging to his career. "I didn't sign up [to the newco] because of the problems they are going to encounter and the sanctions which are going to be put on the club."
TUPE legislation is clear that companies have to inform employees about their contracts being transferred during a change of company ownership, and that the employee has the opportunity to object. If he or she does, the contract is at an end. The players' representatives, legal advisors and union, PFA Scotland, have instructed Naismith and Whittaker that there is no breach of contract, although Green last night insisted the club would pursue transfer fees for them when they join their next clubs.