Career
Born in Osijek, Dubac started his career with Hajduk Osijek before moving to Slavija Osijek. From 1937 he played with BSK Beograd where he became one of the best full-backs in the country and became a regular in the national team When the Second World War started in Yugoslavia, and then he moved to HŠK in the Croatian First League in 1941.
After retiring he became a coach, and coached NK Proleter Osijek, NK Čelik Zenica and NK Trešnjevka.
He later became a dentist. He died in Osijek in 1985.
Internationally he played 14 games for the Kingdom of Yugoslavia and all 15 games which the independent Croatian national team played during the Second World War.