Annunen recently concluded his season with Karpat in Finland’s top professional league, going 7-9-7 with a 2.43 goals-against average and a .880 save percentage. The 6-foot-4, 210-pound netminder led the league in the 2019-20 campaign with a 1.77 GAA and .929 save-percentage. He also established a new league record for the longest shutout streak in a single season at 302 minutes, five seconds.
In addition to his time professionally, Annunen represented Finland at the 2020 IIHF World Junior Championship, where he finished the tournament with a .916 save percentage and a 2.65 goals-against average in six contests. He also helped Finland capture the gold medal at the 2018 IIHF U18 World Championship, registering a 6-0 record with a 2.00 goals-against average and a .914 save percentage in six games.