Scotland manager Craig Levein will delay naming his squad for the make-or-break Euro 2012 qualifier with Spain until Tuesday morning.
As many as five players could be out for the match, including captain Darren Fletcher (ankle), Kenny Miller (groin), Craig Mackail-Smith (back) and Barry Bannan (heel).
"Where to start? The most doubtful will be Kenny. He hasn't improved from Friday until today [Monday]. I'm not definitely ruling him out but he would be the most doubtful," Levein told reporters today.
"Darren Fletcher and Craig Mackail-Smith will do a little bit today and will have fitness tests tomorrow. I am more hopeful with those two than Kenny, but as yet I can't give any definitive answer.
"Barry will do a little bit today. His problem is whether he can get his boot on so it doesn't open up the injury again – it is in an awkward place. We are hopeful that we can put some sort of padding or strapping that will prevent it from opening up tomorrow.
"It is very difficult when there are so many important players who are doubtful. So it will be tomorrow before I find out."
The Scots need a victory over the world champions to secure a place in the playoffs.