Whittaker was substituted during half-time of Rangers' Scottish Premier League win against St Mirren with a hamstring strain, while Thomson has been ruled out after failing to recover from a sickness bug.
Those withdrawals have seen Blackpool midfielder Charlie Adam recalled for the clash in Cardiff.
Whittaker was substituted during half-time of Rangers' Scottish Premier League win against St Mirren with a hamstring strain, while Thomson has been ruled out after failing to recover from a sickness bug.
Those withdrawals have seen Blackpool midfielder Charlie Adam recalled for the clash in Cardiff.