Depleted Scotland will face Cyprus and Kazakhstan without skipper Andy Robertson , Ryan Fraser and Scott McTominay.
Steve Clarke has moved to address the call offs by bringing in Celtic winger Lewis Morgan and Derby midfielder Graeme Shinnie.
Leeds skipper Liam Cooper had already withdrawn before the triple body blow was announced on Tuesday morning.
Clarke is already without Arsenal star Kieran Tierney with the left-back looking to manage his workload after his first extended run in the Gunners side following summer double hernia surgery.
But the loss of Robertson who starred in Liverpool 3-1 win over Manchester City on Sunday is significant ahead of the final two fixtures of an abject qualifying campaign.
Fraser played in Bournemouth's defeat to Newcastle on Saturday and McTominay was stretchered off at the final whistle of United's win over Brighton.
Ole Gunnar Solskjaer admitted the the midfielder could face a spell on the sidelines after picking up an ankle knock.
