Those withdrawals have seen Blackpool midfielder Charlie Adam recalled for the clash in Cardiff.
Scotland coach George Burley said: "Kevin is still laid low with a virus after one or two of the Rangers players were affected after their European game.
"The doctor looked at him this morning and he is still not 100%. We were hoping to take him with us tomorrow but unfortunately he is still laid low.
"Steven Whittaker has a hamstring injury and will not be available either.
"We have called Charlie Adam into the squad who did very well at the weekend and scored a cracking goal for Blackpool.
"He is a very good replacement, he has been playing very consistently, he is a quality player and he is getting a real benefit from playing regularly."
Burley will also continue to monitor the sickness of captain Darren Fletcher, who has been troubled with an ankle problem recently.
He added: "We will train tomorrow and see how everyone is.
"It's nice to get the squad back together again and this is a game we are all looking forward to."
Goalkeeper Craig Gordon was already forced to withdraw after suffering a fracture to his arm, resulting in a recall for St Mirren goalkeeper Paul Gallacher.