 Marjanović aive nhengo yeSerbia U-18 national basketball timu iyo yakahwina menduru yegoridhe ku2017 FIBA Europe Under-18 Championship. Mumitambo minomwe yemutambo, akaenzana 6 mapoinzi, 3 rebounds uye 0.9 inobatsira pamutambo. Aive nhengo yeSerbia U-16 yenyika basketball timu iyo inotora chikamu mu2014 uye 2015 FIBA Europe Under-16 Championship. Pamitambo mipfumbamwe yemutambo wa2015, akaenzana 14.1 mapoinzi, 3.2 rebounds uye 1.1 anobatsira pamutambo. Marjanović aive nhengo yechikwata cheSerbia pasi pemakumi maviri chakapedza gumi neshanu pa2019 FIBA U20 European ChampionshipmuTel Aviv, kuIsrael. Mumitambo minomwe yemutambo, akaenzana 7.1 mapoinzi, 1.9 rebounds, uye 0.9 inobatsira pamutambo. 