 He started in the youth categories of Internacional, known only by his first name, Marcelo.Inter's president at the time, Fernando Carvalho, suggested the change to only Labarthe, the surname of his French origins, because it could be more attractive for the European leagues, where the boy could get dual citizenship (in a similar case of his fellows from Inter's youth team, Rafael Sobis and Marcos Camozzato).When he went to the main team, he used his first name along with his last one, Marcelo Labarthe.