The 39-year-old was on target in last month's triumph over Steve Clarke's side and also made the net bulge on Saturday, as Roberto Martinez's men conquered Poland 3-1 to maintain their 100% record in League A Group 1.
Having been taken off with just 63 minutes gone against Poland, Ronaldo should be given the green light for back-to-back starts on Tuesday, although there may be one alteration in the final third.
Martinez may be reluctant to start Pedro Neto twice in the space of four days given his perpetual fitness woes, so Diogo Jota could now join Ronaldo, Rafael Leao and Bruno Fernandes in the attacking quartet.
With Joao Palhinha omitted from the squad on Saturday, Ruben Neves and Bernardo Silva started at the base of the midfield, and that pairing should be seen again from the first whistle in Glasgow.
Even though Antonio Silva offers a more natural presence at centre-back, Chelsea's Renato Veiga - who had never been capped at senior level before this month - began in the middle of the backline against Poland.
The Blues new boy has likely done enough to hold his place at the back, where Diogo Costa, Diogo Dalot, Ruben Dias and Nuno Mendes are primed to join him.
Portugal possible starting lineup:
Costa; Dalot, Dias, Veiga, Mendes; Silva, R. Neves; Jota, Fernandes, Leao; Ronaldo
Lyon 
Steaua Bucuresti 
Manchester Utd 
Real Sociedad 
Rangers 
Fenerbahce 
Tottenham 
AZ Alkmaar 
Chelsea 
FC Copenhagen 
Fiorentina 
Panathinaikos 
Paris 13 Atletico 
Bordeaux 
Udinese 
Verona 
FC Augsburg 
VFL Wolfsburg 
Union Berlin 
Bayern Munich 
Werder Bremen 
Borussia Monchengladbach 
Everton 
West Ham 
Manchester City 
Brighton 
Mallorca 
Espanyol 
Lokomotiv Moscow 
Dinamo Moscow 
Avranches 
AC Milan 
Como 
RB Leipzig 
Borussia Dortmund 
Villarreal 
Real Madrid 
Angers 
Monaco 
Guingamp 
FC Porto 
Avs Futebol Sad 
Waalwijk 
PSV 
Girona 
Valencia 
Akron Togliatti 
CSKA Moscow 
Venezia 
Napoli 
Celtic 
Arsenal 
Fulham 
Twente 
Feyenoord