Born in Metkovic, Croatia, Petković began his youth career with Dinamo Zagreb, where he remained until 4 September 2009, when he transferred across town, to the youth academy of city-rivals NK Zagreb.
Petković was born in Metkovic, Croatia. Petković began his youth career with Dinamo Zagreb. He remained until 4 September 2009. He transferred across town. This was to the youth academy of city-rivals NK Zagreb.