Popović made his international debut at the 1990 World Junior Championships in Athletics, where he ran in Heat 6 of the men's 100 meters as well as in Heat 5 of the men's 200 meters. In neither distance did he make it into the semifinals. When he moved to Moscow, he continued training with Dynamo Sports Club. When he studied for his master's degree at Florida State, he trained with the varsity team but was not NCAA eligible, so he ran unattached at college track meets. Upon returning to Yugoslavia from his graduate studies in the United States, he was called up as a member of Yugoslavia's 4 × 400 metres relay team for the 1997 Mediterranean Games, which placed last at the competition. His competitive sprinting career ended in 1999 with a meniscus injury. His personal record in the 200 meters was 21.73 seconds with no wind aid.