Town central defender Cameron Burgess played the full 90 minutes as Australia thrashed Indonesia 5-1 in Sydney this morning.
Burgess was winning his 14th full cap against the Indonesians with Blues defender Elkan Baggott not in the squad having preferred to stay behind with loan side Blackpool but reportedly in new manager Patrick Kluivert’s plans.
The Socceroos, who remain second in the qualification group, are also in action against China in Hangzou on Tuesday.
Burgess is the first of potentially eight Town players to win caps today. This evening, Blues pair Dara O’Shea and Jack Taylor could add to their Republic of Ireland caps in their Nations League play-off first leg against Bulgaria in Plovdiv (Amazon Prime, KO 7.45pm).
Heimir Hallgrimsson's side are aiming to keep their place in League B having finished third in Group B2 behind England and Greece. The second leg is at the Aviva Stadium on Sunday.
O’Shea has previously won 32 Irish caps, usually operating at right-back, while Taylor made his senior international debut in October.
George Hirst could make his international debut when Scotland play Greece in the first leg of their Nations League play-off in Piraeus (BBC One Scotland/iPlayer KO 7.45pm). The second leg is at Hampden Park on Sunday.
If Hirst does play, he will become the fifth Town player to have won senior caps with the Scots, following George Burley, John Wark, Alan Brazil and Christophe Berra.
Keeper Cieran Slicker is also part of Steve Clarke's squad, but the 22-year-old seems unlikely to make it onto the field for his first full cap.
Blues loanee Julio Enciso is with the Paraguay squad for their World Cup qualifier against Chile in Asunción.
Enciso, who is on loan with Town until the end of the season from Brighton, has previously won 23 caps, scoring two goals.
The 21-year-old will become the first player to have represented Paraguay while at Portman Road if, as is likely, he is involved against the Chileans.
With six games left to play, Paraguay, who travel to take on Colombia next Wednesday, are currently sixth in the South American qualification group with the top six qualifying for the finals. The seventh-placed side go into a play-off tournament.
Keeper Aro Muric could make his 43rd senior appearance for Kosovo when they take on Iceland in the first leg of their Nations League play-off in Pristina. They travel to Spain for the second leg on Sunday.
Blues youngster Rio Morgan, 19, is with the Northern Irish U21s for a mini-tournament in Turkey and could win his first cap at that level in their opening game against Moldova this afternoon. The game is live on YouTube channel.