The lavishly-lauded Dutch-based winger was assiduously courted by his father's homeland Bosnia and Herzegovina before receiving a shock call-up for a momentous Socceroos month, kicking off with next Thursday's World Cup qualifier against Saudi Arabia in Adelaide.
The 20-year-old former South Melbourne junior will be forever tied to Australia should he garner any match minutes against the Saudis, Brazil or at the Confederations Cup.
But even if that doesn't happen, Hrustic told The World Game the only flag he will be flying from now on is green and gold.
Dubbed an X-factor talent by compatriot and ex-Groningen teammate Jason Davidson, Melbourne-raised Hrustic couldn't conceal his delight at making the cut for the 23-man squad announced by coach Ange Postecoglou on Wednesday.
"I am looking forward to flying out and just can't wait to get it all started now," said Hrustic, who marked his seven appearances for Groningen this season with a stunning strike against PEC Zwolle.
"I've made my decision and I'm really proud to have got this chance with Australia.
"When they came to me I didn't even hesitate.
"It was all over the media saying there was a tug-of-war and stuff but I knew from the first day what I wanted to do and where I wanted to play.
"I wasn't expecting this call up but you take things as they come and hopefully I will take the chance."
Hrustic excelled at a development camp in Spain under the tutelage of Olyroos coach Josep Gombau in March, forming an instant rapport with the former Adelaide United coach, who is also a Socceroos assistant.
And that went a long way to warding off the overtures of the Bosnians.
"In the back of my mind I had Australia after the camp with Josep ... I had a great connection with him and he will be there in Adelaide when I arrive in camp on Friday," he added.
A junior with Schalke before furthering his football education in the Netherlands, Hrustic still remembers being part of an elite training camp conducted by Postecoglou in Melbourne when he was just 12.
"I was just a little boy running around a football field back then and I am sure I was a pain in the ass," he recalled.
"Those types of things you never forget."
Though he operates in a more offensive role, it was not lost on the youngster that overseas success stories like Mustafa Amini and James Jeggo missed out while he survived when Postecoglou cut seven names from his preliminary 30-man squad.
"I saw some of the players who have been doing well in Europe missed out and it's a shame for them," he said.
"But it's also a good thing for the coach who has a massive group of players to pick from.
"For me, it's a great thing to be a part of the squad."
Hrustic is confident that, if called upon, he is ready to make a meaningful impact.
"I like to take risks when I attack and make every action count every time I'm on the ball," he explained.
"I'm always out to score or assist and of course my game is still developing."
Hrustic is keen to make the acquaintance in the flesh of players he has enjoyed watching while growing up.
"As soon as you stand on the fiend with players like this, it's an honour, a great feeling," he added.
"I won't name any but there are a few of them."
Asked if nerves might be jangling when he trains with his new teammates for the first the first time, Hrustic replied: "Not really, that's not my character.
"I just want to go on the field and play."
The prospect of facing Brazil in his hometown of Melbourne is almost as enticing as the Saudis Adelaide for Hrustic.
"It's where I was born and I haven't been back in a few years," he said.
"I am feeling confident and just can't wait to get on the pitch (for my debut)."