Kieran Tierney suffered a head knock in the win over Republic of Ireland on Saturday nightVenue: Cracovia Stadium, Krakow Date: Tuesday, 27 September Kick-off: 19:45 BSTCoverage: Listen on BBC Radio Scotland Extra/DAB/810MW, live text commentary on the BBC Sport website & app, highlights on BBC One Scotland at 22:40Scotland will be without defenders Kieran Tierney and Scott McKenna for Tuesday's Nations League decider with Ukraine.
The duo have dropped out of Steve Clarke's squad for the game in Krakow, Poland, along with suspended midfielder Scott McTominay.
Hearts pair Barrie McKay and Stephen Kingsley have been called up.
Scotland will win Group B1 if they avoid defeat, while Ukraine need three points to finish on top.
Arsenal full-back Tierney and Nottingham Forest centre-half McKenna both started last week's 3-0 win over Ukraine in Glasgow and Saturday's 2-1 success against the Republic of Ireland.
However, Tierney was replaced after a head knock during the first half against the Irish.
Captain Andy Robertson was already missing through injury, leaving Celtic's Greg Taylor likely to take over at left-back.
Nathan Patterson started at right-back against Ukraine but was stretchered off after damaging his knee. His replacement, Aaron Hickey, was then taken off after pulling up against the Republic, but the Brentford player remains with the squad.
McKenna played for the duration of both matches at Hampden.
Kingsley, capped once in 2016, offers an alternative at left centre-half, along with St Mirren's Declan Gallagher, who was called up after the win over Ukraine on Wednesday.
With Grant Hanley and Liam Cooper also sidelined, Ryan Porteous is the only other central defender available to Clarke, but the Hibernian player remains uncapped.
Hellas Verona left-back and Scotland under-21 captain Josh Doig was drafted in before the win over the Republic, but he too has never been involved at senior level.
McKay's only Scotland appearance so far came in the same 2016 friendly loss to France that Kingsley featured in, with the Tynecastle winger an 88th-minute substitute.
