Dee ihe na-aga n'ihu maka paragraf a - Barnes meriri ọla edo na United States na 2017 FIBA Under-16 Americas Championship na Formosa, Argentina mgbe ọ gbasịrị akara 9.8, 3.2 rebounds na 2.4 na-ezu ohi kwa egwuregwu. Na mmeri ha meriri Argentina na ọkara-ikpeazụ, o duziri ndị niile na-agbakọ ihe na 20 isi na isii na-ezu ohi mgbe ọ na-agbaji ihe ndekọ America n'okpuru 16 maka pasent na-atụba n'efu site n'ịgba 8 nke 8 site na akara ntụgharị. Na 2018 FIBA Under-17 World Cup na Argentina, Barnes nwere akara 9.5 na 5.8 rebounds kwa egwuregwu ma weghara ọla edo ọzọ. O nwetara akara 9.7, 4.9 rebounds na 2.7 assists kwa egwuregwu na 2019 FIBA Under-19 World Cup
na Heraklion, Gris, ebe o meriri ọlaedo nke atọ ya na United States.