 Born in Thun, Switzerland to a family of Bosnian Serbs expats (his father hails from a small village called Skugrić near Modriča, Bosnia and Herzegovina, SFR Yugoslavia), Kuzmanović continued the family tradition as both his father Ljubo and his grandfather played football for the lower league in Bosnia and Herzegovina at the local club in Gradačac – FK Zvijezda where he started his football career.Kuzmanović's father also played professionally in Berlin, before eventually ending his career at FC Thun of Switzerland, and continuing to live in the country.Kuzmanović started his professional career at Basel, having played in the academy for Dürrenast and Young Boys before moving to Basel.