While he trained basketball at young age, Opačić played at a point guard position, and his role model was Zoran Moka Slavnić.

Opačić was assistant to maintenance director at PVC Petrohemija in Pančevo from 1987 to 1988 and a senior independent constructor at the Military Technical Institute Belgrade from 1988 to 1994.

From 2011 to 2019, he was an FIBA expert associate at its headquarters in Geneva and as the head coach of the Tamil Nadu state team from Chennai he won the Indian National Basketball Championship in 2018.

Željko Obradović, Dušan Ivković, Duško Vujošević, Igor Kokoškov, Svetislav Pešić, Aleksandar Đorđević and others took part in the work of this camp, whose promoter is Vasilije Micić.

[12] Milan Opačić is a participant and organizer of relevant coaching seminars with Don Nelson, Gregg Popovich, Larry Brown, Rubén Magnano, Ettore Messina, Pini Gershon, Pablo Laso, Sergio Scariolo, Svetislav Pešić and Božidar Maljković.