Angus Gunn has been ruled out of Scotland’s Nations League matches against Croatia and Portugal.
The Norwich goalkeeper emerged as a major doubt after taking a heavy knock in their Championship clash against Hull on Saturday that saw him replaced at half-time.
The goalkeeping position is a headache for manager Steve Clarke but Kilmarnock’s uncapped Robby McCrorie has been given the nod after returning from injury against Dundee at the weekend.
Clarke had previously named Hearts’ Craig Gordon and Jon McCracken of Dundee in the squad.
Aberdeen defender Jack MacKenzie, meanwhile, comes into the group for the first time to replace Celtic’s Greg Taylor, who misses out with a calf injury.
Left-back MacKenzie, 24, has been rewarded for Aberdeen’s flying start to the season with a first call-up for Scotland at any level.
Scotland, who lost both their opening Nations League fixtures, take on Croatia away on Saturday before a home match against Portugal next Tuesday.