Scotland have called up Aberdeen defender Mark Reynolds for Sunday's 2016 European Championship qualifier against Germany in Dortmund.
The uncapped 27-year-old was drafted in by manager Gordon Strachan after Christophe Berra remained at Ipswich for treatment on an injury.
Celtic's Charlie Mulgrew is also nursing a knock.
But the versatile 28-year-old is expected to join in training later in the week.
"Christophe is being looked at by his club but we are still hoping that he will show," explained assistant manager Mark McGhee.
"We have brought in Mark Reynolds as a precaution. Mark was unfortunate not to be in the squad in the first place, he is certainly one of a short list that could have been in the squad.
"Charlie is here. He won't train in the early part of the week but we expect him to be available for selection."
McGhee was full of admiration for Germany but stressed that does not mean Scotland cannot surprise the World Cup winners in their Group D opener.
"I don't think there are any weaknesses," said McGhee.
"What there are, is opportunities. At some point in the game we will have the ball and it is what we do with it then.
"We can't wonder if the right-back or the right centre-half is a weakness.
"They don't have weaknesses but that doesn't mean to say that we can't be successful against them."
McGhee, who played in Germany with Hamburg, is hoping for a Scotland goal-scoring hero to emerge, much in the same way that James McFadden's 2007 winner against then World Cup runners-up France in a European Championship qualifier in Paris was celebrated.
"The guys who are likely to score will be dreaming about it, I hope they are," said the 57-year-old former Aberdeen and Celtic striker.
"As a player I lay in bed in the morning before the game or the night before the game, thinking about hitting the winning goal or getting an important goal.
"It is not something you can plan for, it will happen if it is going to happen.
"But we will put out a team that will contain three, four, maybe even five players who would be capable of scoring that goal.
"I think that is really important because I think you have to have a chance of doing that."