AC Milan move fast to secure Andrej Kostić
AC Milan have agreed a deal to sign Andrej Kostić from Partizan Belgrade on a permanent transfer, with the 19-year-old now in Milan for his medical after the agreement was sealed. Fabrizio Romano relayed the news, citing Luca Maninetti, with the move presented as done after Milan beat several clubs to the striker’s signature.
The transfer fits Milan’s recent approach of mixing senior-market targets with high-upside young signings who can either develop into first-team assets or rise sharply in value over the next few years.
Who is Andrej Kostić?
Kostić is a Montenegrin striker born on 16.06.2006, currently with Partizan Belgrade. He is one of the more intriguing young centre-forward profiles to emerge from the region, with a reputation built around penalty-box instincts, strong finishing potential and the kind of physical and technical base top clubs like to secure early.
At 19, he is still clearly a development-stage signing rather than a finished first-team solution, but that is exactly what makes this move interesting. Milan are buying trajectory as much as present output.
The agency behind the deal – International Sports Office
Kostić is represented by International Sports Office (ISO), the Belgrade-based agency that has become increasingly visible in Balkan-to-top-league pathways. On FootballAgencies.com, ISO is described as a firm built around elite representation and pathway development, with strong club relationships and full off-field support.
A key name inside the agency is Darko Ristić, listed as Executive Director and Licensed Agent. He is described as the decision maker who leads representation operations and deal execution, which makes him one of the central figures behind moves like this.
The agency is also well known for representing Dušan Vlahović, which adds extra weight to its reputation when handling high-level striker careers from the region.
This looks like more than a simple youth gamble. Kostić gives Milan an early foothold on a player who was attracting broader interest, and the ISO connection matters because it places the club in direct contact with an agency deeply embedded in the Balkan market and already associated with one of Europe’s biggest Serbian striking names.
That does not mean bigger names automatically follow, but these relationships matter in football. One deal often opens doors for the next conversation.
The medical is the next major step, after which Milan can complete the formal signing and announce the player. The bigger question will then be sporting integration: whether Kostić is developed gradually through a secondary team pathway or pushed more aggressively toward senior involvement. Either way, Milan have moved early on a striker they clearly believe has significant upside.
