The 'pretty special' 17-year-old out to dash Scotland dreams

Konstantinos Karetsas has switched allegiance from Belgium to Greece

Scotland take a hard-earned 1-0 lead into Sunday's second leg at Hampden Park, but no-one in their ranks is taking overall victory for granted.

Greece were a much-improved side in the second half in Athens, in no small part thanks to the half-time introduction of 17-year-old Konstantinos Karetsas.

The teenager from Genk in Belgium was given his debut by manager Ivan Jovanovic and immediately helped swing the momentum in the home side's favour.

Thankfully for Scotland, he could not quite create or score an equaliser, one curling effort clearing the crossbar by inches and his beautiful, teasing cross knocked on to the post by Christos Tzolis.

So exactly who is this Greek wonderkid?

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."

Karetsas relishing Robertson challenge

Karetsas himself clearly does not lack confidence.

"Already, I feel like I belong in the national team. I'm really happy I made the decision to be here," he said afterwards.

"I was up against Andy Robertson. He is a very good player, but when I go one on one, I don't see who's in front of me.

"We lost, but we played well in the second half and that is how we have to play on Sunday in Scotland. I think, if we play like that, we will win."

Trying to ensure that does not happen will be Craig Gordon, who acknowledged the threat his young adversary posed.

"He looked fantastic when he came on," said the Hearts goalkeeper. "He's someone we'll need to look out for in the second leg.

"I haven't seen many debuts like that from someone so young. It was an impressive first cap for him, but thankfully we managed to keep him out.

"We'll see what Sunday brings and he might get more minutes at Hampden. But I'm sure we'll have a plan to deal with that as well."

McFadden does not believe head coach Clarke will adapt his gameplan to deal with the teenager.

"I think you respect the fact he's a very good player, but it's Andy Robertson that's going to be playing against him," McFadden said.

"I think if you said to him, 'I'm going to get someone to help you with this young player', I don't think he'd be too happy."

Nevin added: "I think he'll consider it, because if you don't consider it and he has a great game, you've made a mistake.

"I think it's more, don't change your entire attitude but be very aware, if it starts being a problem, you can adapt to it."