 Shirokov akaita mutambo wake wekutanga nenyika yeRussia ku2003 U-18 Junior World Cup, achiwana menduru yesirivha apo achipa mapoinzi mana mumitambo mishanu. Akaenderera mberi achitamba nechikwata chenyika cheU-18, achibatsira Russia kuwana zvinyorwa zvakanakisa pa2003 Four Nations uye 2004 Five Nations Tournaments. Pa 2004 IIHF World U18 Championships, akabatsira Russia kune imwe menduru yegoridhe muMinsk, Belarus, ichikunda United States 32 mufainari. Shirokov akapinza zvibodzwa zviviri mumitambo mitanhatu. 