Illa spent 2011 and 2012 seasons in FC Gomel. FC Torpedo Zhodino was his first club where he played in 2007-10 seasons. In the Vysshaya Liga Aleksiyevich played 72 matches, scored 5 goals and gave four assists. In the Belarusian Cup he recorded 14 matches and 1 goal. In European Club Competitions his statistics is 8 games, 2 goals.
In Gomel he won the Belarusian Cup (2011) and Belarusian Supercup (2012), and won bronze medals of the Belarusian Championship (2011). Debuted in the national team in a friendly match against Israel in November 2012. Played for U21 national team (22 matches, 1 goal). Participant of the 2012 London Olympics.