 At the end of the 2000–01 season that saw Red Star win another league title (after winning the league and cup double the previous season), Ratko Dostanić, Muslin's assistant, took the head coaching job at FK Obilić, and Muslin offered the vacated place to Janković who thus became Red Star's assistant coach on 5 July 2001 at the age of 29.However, Janković wouldn't get to stay at his new job for long as very early into the 2001–02 season Muslin abruptly resigned as head coach after the 2001–02 UEFA Champions League qualifying first leg loss to Bayer Leverkusen and Janković left as well.In March 2002, Muslin resurfaced as head coach at Levski Sofia and Janković followed him there to be his assistant.