John McGinn and Scott McKenna volition some miss Scotland's Nations League treble header against Croatia and Portugal done wounded but goalkeeper Craig Gordon has returned to the group.
McGinn, 29, is expected to miss 3 oregon 4 weeks with a hamstring strain picked up successful Aston Villa's triumph implicit Wolves past period and, unusually, is forced to beryllium retired an planetary break.
Centre-back McKenna, 27, has missed Las Palmas' past 3 matches with a hamstring issue. However, midfielder Ryan Gauld - who earned his archetypal 2 caps arsenic a substitute successful September's matches - makes the squad contempt being absent for Vancouver Whitecaps successful caller weeks.
There are archetypal call-ups for Aberdeen full-back Nicky Devlin, Preston North End centre-back Liam Lindsay and West Ham United midfielder Andy Irving.
Scotland look Croatia successful Zagreb connected 12 October earlier Portugal sojourn Hampden 3 days later.
Cristiano Ronaldo's 88th-minute victor successful Lisbon past period consigned Steve Clarke's broadside to consecutive defeats successful Nations League A, aft Poland besides struck precocious to triumph 3-2 successful Glasgow.
It means Scotland person won conscionable erstwhile successful their past 14 outings arsenic Clarke contends with a bid of injuries to cardinal players with Arsenal's Kieran Tierney and Brentford's Aaron Hickey some inactive missing.
Bologna midfielder Lewis Ferguson is lone conscionable returning from a genu wounded which helium suffered successful April.
It was thought goalkeeper Gordon, 41, mightiness person played his past crippled for Scotland erstwhile helium earned his 75th headdress against Finland successful June.
However, having been reinstated arsenic Hearts' archetypal prime goalkeeper this season, Gordon is preferred to his nine team-mate Zander Clark.