Scotland face issues in central defence after Charlie Mulgrew dropped out of the squad for their opening Euro 2020 qualifiers.
Aberdeen centre-back Scott McKenna also emerged as an injury doubt for the games against Kazakhstan and San Marino after playing through a thigh injury on Saturday.
Mulgrew was one of three players to drop out along with Millwall goalkeeper Jordan Archer and Sheffield Wednesday midfielder Barry Bannan.
Scotland squad update: OUT: Jordan Archer, Barry Bannan, Charlie Mulgrew.
IN: Liam Kelly & Stuart Findlay. pic.twitter.com/cdeTGD59Wi
— Scotland National Team (@ScotlandNT) March 17, 2019
Livingston goalkeeper Liam Kelly and Kilmarnock centre-back Stuart Findlay have been handed first call-ups.
Blackburn skipper Mulgrew has missed his club's last two games after suffering a hamstring injury.
And Aberdeen boss Derek McInnes cast major doubt on McKenna's participation for Thursday's Group I opener against Kazakhstan in Astana after the 22-year-old played with a heavily-bandaged thigh during his team's 1-1 draw with Livingston.
McInnes said after the match: "He wasn't fully fit but with Andrew Considine failing a fitness test with his calf, he had to go in. He'll be a doubt for the Scotland game.
"If he does travel, I'm not sure he'll be fit for that first game. The tightness of the thigh, the travelling, the astroturf pitch. I wouldn't want to rule him out – I'm not a medical expert.
"We need to make a decision between us and Scotland whether he travels."
Findlay was a Scotland Under-21 regular and has impressed under Steve Clarke at Kilmarnock. The other two centre-backs in the squad are John Souttar of Hearts and Hamburg's David Bates.
💫 Those assists yesterday 👌 #swfc pic.twitter.com/ad0kscjrQo — Sheffield Wednesday (@swfc) March 17, 2019
Archer was dropped from the Millwall team for the midweek victory over Birmingham and was not in the squad for Sunday's FA Cup quarter-final defeat to Brighton.
Bannan – who has not featured under Scotland boss Alex McLeish – played the full 90 minutes and set up three goals as Sheffield Wednesday beat Blackburn 4-2 on Saturday.
There was better news for McLeish as key midfielder Callum McGregor played the full game as Celtic beat Dundee 1-0. The 25-year-old had been missing for four matches with a calf problem.