Well, actually, he was born in Belgium and has lived and played there all his short life. Born to Greek parents in Genk, Karetsas joined their academy and quickly accelerated through the ranks to make his first-team debut at the end of last season as a 16-year-old substitute against Cercle Brugge. He started for the first time in a win over Royal Antwerp two weeks later.
This season, he has been a first-team regular, starting 14 and coming on in another 11 games, mainly as an attacking midfielder and helping Genk to the top of the Jupiler Pro League.
Karetsas represented Belgium at youth level, playing for their under-21s as recently as November.
But, as Greek journalist Stephen Kountourou explained on BBC Scotland’s Daily Football Podcast, there was a wrangle going on behind the scenes.
“We had to fight tooth and nail with the Belgian FA to stop him representing them and that was seen as a big coup for Greek football, because Karetsas is rated not just as a potentially decent talented player but as one of the big players for the future in international football,” he said.
For Karetsas, whose idols include Neymar and Ronaldinho, there seemed to be little doubt as to whom he would represent at senior level.
“My heart beats only for Greece – my homeland fulfils me completely,” he was quoted as saying.
He was warmly welcomed into the fold by the Greek fans on Thursday and his performance was so impressive BBC Scotland’s co-commentator James McFadden fully expects him to start at Hampden.
“I thought he looked really classy, composed, willing to take people on and, when he came on, he was their main outlet,” he said. “They were just desperate to get the ball to him, so I think he comes straight into the team.”
Pat Nevin, working at the game for BBC Radio Scotland and Five Live, was similarly impressed.
“I thought he made a huge difference, probably the main reason the game changed massively in the second half,” the former Scotland winger added.
“Chatting to Steve Clarke afterwards, he agreed the young lad is pretty special and somebody that needs to be kept a really close eye on.”
