Kevin Thomson, Kevin McNaughton and Callum Davidson have pulled out of the Scotland squad.
Stewart drafted in by Burley
Scotland manager George Burley's preparations for the World Cup qualifiers against Macedonia and Iceland this week have been further disrupted by three more withdrawals.
Cardiff defender Kevin McNaughton and midfielders Callum Davidson, of Preston, and Kevin Thomson, of Rangers, have all pulled out because of injury.
Hearts midfielder Michael Stewart is the only player who has been called up as a replacement.
David Marshall, David Weir and Garry O'Connor all pulled out of the squad on Monday to be replaced by Jamie Langfield and Kirk Broadfoot.
