Scotland are short of left-backs for their Euro 2020 qualifier in Kazakhstan after Kieran Tierney was ruled out through injury.
Manager Alex McLeish was already without skipper Andy Robertson following the Liverpool player’s withdrawal due to dental surgery.
Celtic’s Tierney was set to deputise for Robertson, but will now miss Thursday’s match due to an apparent hip problem, the Scottish Football Association has announced.
Tierney played through a niggle during Celtic’s win over Dundee on Sunday.
The 21-year-old sat out training in an indoor arena in Astana on Tuesday, undergoing some work on his own back at the team hotel, but has failed to recover in time.
Robertson missed the team flight to Astana to have treatment on Monday and was told by medical staff that he needs more time for his mouth to settle down.
However, he will be available for Sunday’s second Group I qualifier against San Marino.
McLeish said: “Kieran has been ruled out of this game. We did a medical on him and he had a scan and he can’t be risked at this stage.”
Callum McGregor has been named skipper in the absence of Robertson.
McLeish said: “Over the past few years Callum has shown tremendous ability on the field but also he is a very good ambassador of football on and off the pitch. An unfussy player, nothing seems to bother him.
“He is a great example to the rest of the squad in his professionalism and I believe the players will respond to Callum being the skipper for this one.”