George Hirst made his Scotland debut as a second half sub as his side beat Greece 1-0 in the first leg of their Nations League play-off in Piraeus, while Dara O’Shea, Jack Taylor and Aro Muric added to their international caps.
Hirst, whose switch of allegiance from England was confirmed last week, came on in the 68th minute, Scott McTominay having given the Scots the lead from the penalty spot on 33.
The 26-year-old striker is the fifth Town player to win a senior Scotland cap, following George Burley, John Wark, Alan Brazil and Christophe Berra.
Blues keeper Cieran Slicker was an unused sub, while the teams meet for the second leg at Hampden Park on Sunday.
O’Shea started for the Republic of Ireland and won his 33rd full cap as his team came from behind to beat Bulgaria 2-1 in the first leg of their Nations League play-off in Plovdiv.
Taylor came on in the 76th minute to win his second cap. The sides face one another in the second leg in Dublin on Sunday.
Keeper Muric played the full 90 minutes and won his 43th cap as Kosovo beat Iceland 2-1 in the home leg of their Nations League play-off in Pristina. They travel to Spain for the second leg on Sunday.
Julio Enciso’s Paraguay are in action in a World Cup qualifier at home to Chile at 11pm with the on-loan Brighton man starting.