Steven Naismith has been suspended by FIFA for Scotland's forthcoming World Cup double-header.
A disciplinary panel found the forward guilty of elbowing Serbia's Srdjan Mijailovic during last month's goalless draw at Hampden Park.
And a two-match ban rules Naismith out of Group A qualifiers against Wales in Cardiff on 12 October and Belgium in Brussels on 16 October.
Scotland manager Craig Levein said: "Obviously this is disappointing news, but Steven has been very honest and professional throughout the disciplinary process.
"We named a 25-man squad to compensate for any potential suspension, which has now been confirmed.
"I am confident we have enough strength in that department to offset the loss of a player who has been in excellent form so far this season."
Naismith's absence increases the likelihood of Sunderland's Steven Fletcher featuring for Scotland for the first time since August 2010.