Januzaj qualifies to play for Albania, Serbia, Turkey and Belgium.
The youngster's mother is from Croatia, so Januzaj also qualifies for their national team. He could also decide to wait until Kosovo are recognised by FIFA or UEFA and play for them.
England are also reportedly interested and he could play for the Three Lions as early as 2016 through residency.
"One of the managers from Albania has told me that Adnan's mother is from Croatia so we are of course interested in him," Croatian Under-21 manager Ivo Susak told Sportske Novosti.
"His potential is amazing but we know we are facing an uphill battle for him.
"As for now he has no Croatian papers so this is an important issue. We are yet to speak with him but we are of course planing talks with this young player."