Donika represented Russia in international competition at the junior level. He played in three consecutive world junior tournaments, playing in 20 games total, and recording three assists. At the 1997 World Junior Championships, he helped Russia capture the bronze medal. In 1998, Russia lost to Finland in overtime during the gold medal game, settling for silver. The 1999 World Junior Championship was Donika's last year of junior eligibility. At the tournament in Winnipeg, Manitoba, Donika and his Russian teammates captured the gold medal by defeating Canada in overtime. With the victory, Donika and his teammate Roman Lyashenko became the only two players in the history of the World Junior Championships to capture gold, silver and bronze medals.