Striker Che Adams has withdrawn from the Scotland squad for Nations League games against Poland and Portugal but Rangers midfielder Connor Barron has been given a first call up.
Celtic pair James Forrest and Greg Taylor join Adams in pulling out of Steve Clarke's group, along with goalkeeper Robby McCrorie.
Barron and Sassuolo left-back Josh Doig have been promoted from the under-21s as cover, with Dundee goalkeeper Jon McCracken already drafted in to replace McCrorie.
Adams, 28, started all three of Scotland's group games at Euro 2024 before moving to Torino in Serie A, where has scored one goal in four appearances so far.
His absence leaves Lyndon Dykes, Tommy Conway, and Lawrence Shankland as centre forward options for Clarke.
Barron, meanwhile, moved from Aberdeen to Rangers and has started six of the Ibrox club's seven games so far this season.
He and Doig could make their senior debuts as Scotland host Poland on Thursday night before a trip to Portugal on Sunday in Nations League A.