|Venue: Cracovia Stadium, Krakow Date: Tuesday, 27 September Kick-off: 19:45 BST|
|Coverage: Listen on BBC Radio Scotland Extra/DAB/810MW, live text commentary on the BBC Sport website & app, highlights on BBC One Scotland at 22:40|
Scotland will be without their two defenders for Tuesday's decider.
Scott McTominay and the duo have been dropped from the squad for the game in Poland.
They have been called up.
Scotland will win the group if they don't lose.
In last week's win over Ukraine and Saturday's victory against the Republic of Ireland, both full-backs and centre-halves were in the starting line-up.
During the first half of the game, Tierney was knocked out.
Greg Taylor is likely to replace Andy Robertson at left-back.
Nathan was taken to the hospital after damaging his knee. The player who was taken off after pulling up against the Republic is still with the team.
Both games were played at the same time.
There is an alternative at left centre-half with the addition of St Mirren's Declan Gallagher, who was called up after the win over Ukranian.
Ryan Porteous is the only other central defender available, but he is uncapped.
Josh Doig, Scotland's under-21 captain, was drafted in before the win over the Republic, but he has never been involved in a senior match.
McKay's only appearance for Scotland was in a friendly against France in 2016 and he came on in the 88th minute.