Steven Naismith has become the latest player to withdraw from the Scotland squad for the friendly with Japan.
Rangers ace Naismith becomes the sixth player to pull out of the friendly this weekend after Danny Fox, Kevin Thomson, Robert Snodgrass, Shaun Maloney and Gary O'Connor all withdrew because of injury.
Only 10 players were able to take part in training on Tuesday and Scotland boss George Burley is sweating on the fitness of Scott Brown.
Celtic midfielder Brown has travelled to London to see a specialist over his long-standing ankle problem, but Burley is refusing to rule Brown out of the trip to Japan.
"Scott is in London today to see the specialist, who is assessing his ankle just now," said Burley.
"He is getting scans and we are just waiting to hear what's happening with that."
Several other players are also struggling, but Burley added: "It's too early to say at the moment.
"There are a number with knocks and I think we had a five-a-side at training today.
"But we are assessing the situation and looking at it and the medical people will be looking at the players over the next four or five hours.
"We will see who is going to be fit and, if we need to bring anyone else in, we will do that."
He added: "I won't play anyone who has an injury, I will only play players who are fit and that's why I am looking at it carefully."