Tarasenko made his professional debut with Sibir Novosibirsk in 2008–09, scoring seven goals and ten points in 38 games and was the runner up in voting for Rookie of the Year in the KHL's inaugural season. He was released to play with the Russian junior team at the 2009 IIHF World U18 Championships, where he scored eight goals in seven games and was named a tournament all-star as Russia won silver. Tarasenko returned to Sibir in 2009–10 as the seventh-youngest player in the League. He again represented Russia at the 2010 World Junior Ice Hockey Championships, finishing third in team scoring with five points in six games.