Kammala jumla mai zuwa: An zabi Hart na gaba don wakiltar Kanada a Gasar Hockey ta Duniya ta Junior ta 2017. An kawo shi a matsayin mai tsaron gida, an cire shi bayan ya ba da kwallaye uku a cikin harbi 17 da Rasha ta yi kuma an sake kiransa ne kawai lokacin da Connor Ingram ya ba da kwallaye biyu a cikin harbi uku da Sweden. Bayan ya yi kariya 31 a wasan zinare da Amurka, Hart ya ba da kwallon da Troy Terry ya yi don ya ba Kanada lambar azurfa. An sake zabarsa, tare da Michael DiPietro wannan lokacin, don
Gasar Hockey ta Duniya ta Junior ta 2018. Bayan da ya yi rikodin ceto 23 a kan Jamhuriyar Czech a wasan kafin gasar, an zabi Hart a matsayin mai farawa na Kanada. Kanada ta doke Sweden a wasan zinare, kuma Hart ya ƙare gasar tare da rikodin 5<unk>0<unk>1, yana daidaita rikodin duniya na Kanada a duniya a 8<unk>0<unk>2.