Popović was raised in Lisbon, Portugal where he began his career with CD Olivais e Moscavide in the Segunda Divisão.
Popović enjoyed a stint as an assistant coach with the Cape Verde national team in 2010, before joining Spanish Segunda Division B side AD Ceuta helping guide the club to the Copa del Rey Round of 32 – the club's best ever showing in the tournament falling to eventual runners-up, Barcelona.
On 21 December 2017, it was announced that Popović would take over as head coach of the Ottawa Fury of the United Soccer League.
Nikola brings his very attractive and effective style of football based on possession and high pressure.
[3] With a strong start at the helm of Atlético, he has been highlighted in the Portuguese press for his career and experience in various countries and continents.
Popović is often invited by Portuguese sports and news television channels to comment and analyse national and internationals soccer matches.