Defender Grant Hanley has been ruled out of Scotland's World Cup qualifying double header with a groin injury.
Manager Craig Levein will be without the Blackburn Rovers centre-half for the short trip to the Millenium Stadium on Friday and the visit to Belgium four days later.
Norwich City midfielder Robert Snodgrass is also a doubt with an ankle knock that kept him out of the Canaries' defeat to Chelsea this weekend.
In more positive news, Celtic duo Scott Brown and Charlie Mulgrew should be fit, according to Bhoys boss Neil Lennon.