After his career as a footballer, Ružnić became a football agent with his clients including; Josip Iličić, Jasmin Kurtić, Armin Bačinović, Dalibor Volaš, Aleksander Rajčević, Robert Berić, Aleš Mertelj, Aljaž Struna, Siniša Anđelković, Luka Krajnc, Elvis Bratanović, Anej Lovrečič, Jasmin Handanovič and Anton Žlogar.