The Tartan Army take on group leaders Denmark in World Cup qualifying, with Porteous joining Hibs team-mate Kevin Nisbet in the squad.
The 22 year-old centre-back has caught the eye with some impressive performances for Hibs this season and replaces Scott McTominay, who drops out with illness.
Porteous has made 14 appearances for Scotland Under-21s but could make his senior bow against the Danes - who have a perfect record in Group F, having conceded only once in nine fixtures.
A draw would be enough to confirm Scotland's place in the World Cup play-offs ahead of the tournament in Qatar next year.
Kevin Nisbet has been a regular in the squad since making his debut earlier this year.
On Tuesday, Josh Doig takes on Belgium with Scotland Under-21s, while Martin Boyle's Australia face China.
