Kammala wannan jumla: A watan Yulin 2017, Barrett ya yi kanun labarai tare da maki 38, da 13 da kuma taimakawa biyar yayin da ya jagoranci tawagar 'yan kasa da shekaru 19 na Canada zuwa nasarar da ta yi a kan Amurka a gasar cin kofin duniya ta 99/87
FIBA Under-19 Kwando Gasar cin Kofin Duniya. A lokacin, Northpolehoops.com ya bayyana wannan wasan a matsayin "babban wasan Barrett a cikin aikinsa har zuwa yanzu". Daga baya ya jagoranci Kanada zuwa taken, inda ya zira kwallaye 18 da 12 a wasan zakarun Turai da Italiya, kuma an kira shi zuwa gasar ta All-Star Five da kuma wasan mafi muhimmanci. Matsakaicin maki 21.6 a wasa, shi ne kuma babban mai zira kwallaye a gasar.