Rubuta ci gaba don wannan sakin layi - Massengale ta fara fitowa ta farko a gasar FIBA Americas Under-16 Championship ta 2009 a Mexico. Daga nan za ta ci gaba da wakiltar Amurka a duka gasar cin kofin duniya ta FIBA ta 2010 da kuma gasar cin kofin duniya ta FIBA ta 2011
, ya tafi gida da zinariya a lokuta biyu. A gasar cin kofin duniya ta 'yan kasa da shekaru 19, ta sami gurbi a cikin Kungiyar Kowace Gasar, tare da abokiyar wasanta Breanna Stewart.