Danubio F.C.
Born in Montevideo, Barreto began his career with local club Danubio F.C.. He started with the youth team and in 2009, at the age of 17 made his debut with the first team. His debut came in an away match against Tacuarembó, in which he came off the bench and won a decisive penalty as Danubio claimed a 2–1 victory.