Nyora kuenderera mberi kweiyi ndima - Kostitsyn akamiririra Belarus zvakanyanya pamatanho ari pasi pe-18 uye -20. Akatanga kutamba pasi rose pa2000 IIHF World U18 Championships aine makore gumi nemashanu, asi Belarus yaizotambura muchikamu chepamusoro, ichipedza yekupedzisira. Gore rakatevera, Kostitsyn akakwikwidza nechikwata cheBelarus chepasi pemakore makumi maviri mu2001 World Junior Ice Hockey Championships
' chikamu chepamusoro. Gare gare gore iroro, mushure mekudzingwa kwe2001 IIHF World U18 Championships, Kostitsyn akadzoka kuzorekodha mutambo-kutungamira 14 mapoinzi mumitambo mishanu mukati mechipiri-tier kuhwina mukwikwidzi weDivision I.