Described as a “top talent” with a “big future in Europe”, Duncan carved an impressive cameo off the bench over the weekend as he begins life with AGF Aarhus, home to established Socceroos Mustafa Amini and Alex Gersbach.
AGF’s director of football Peter Christiansen has already seen enough to convince himself that the 19-year-old former Brisbane Roar rookie has an international future ahead of him.
“Surely, if he continues on this path he must get a call up soon - if not for the Socceroos then maybe one of the teams underneath them (the Young Socceroos and Olyroos),” Christiansen told The World Game.
“It must be the case because he most certainly has the quality.
“The 20 minutes he made for us (in the 2-1 loss to Lyngby) confirmed what kind of player he is - and the boy is a big talent.
“He has quick feet and when he turns with the ball and sets tempo ... it’s something that is rare in football and is also one of the attributes that Mustafa Amini has.
“I don’t know why but we have to go to Australia to find it.”
Duncan, who made four appearances for Brisbane last season and was a player the club wanted to keep, has yet to represent Australia at any level.
Ironically, Socceroos and Olyroos coach Arnold was in Denmark the previous weekend to watch AGF against Awer Mabil’s Midtjylland, but Duncan remained on the bench on that occasion.
Having tied him to a four-year deal in June, as he arrived from Brisbane via boyhood club Marconi Stallions, Christiansen is convinced he has acquired an unpolished gem.
“Zach’s adapted very quickly and very well and has the right passion for the game,” he added.
“He wants to prove himself in football and came on the other day determined to make a difference.
“He’s just a hard worker - everything we hoped we’d get we got and he is ahead of schedule in his development with us.
“From the first day he arrived he has come not only to be a part of the squad but to fight for a (first team) position straight away and we like the attitude about that.
“We like his hunger on the training ground and for a footballer if you don’t have that you have a big problem.”
Christiansen sees the former Sydney FC and Western Sydney Wanderers junior as a natural number eight, who can also play deeper if need be.
“He can play different positions and different systems and is good under pressure and on the ball and he has a big work ethic,” he stressed.
“He has good ideas also and it was natural to give him his debut because he’s been looking that well.
“For me, and at this football club in general, it’s not about age but what you want and can give to the team. It was well deserved.
“We like him as a number eight, making deep runs and linking up play with the strikers and wingers.
“He can do a holding role in the future but maybe now is not the position for him because of the responsibility that comes with that.
“He needs to keep working hard and fighting for his position and so far he’s done that.”