Mancuello made his league debut for Independiente in a 1-2 home defeat by Arsenal de Sarandí on 14 December 2008. He scored his first goal for the club im a 5-1 away defeat to Lanús on 5 April 2009. He scored again on 11 April in a 2-1 win over Huracán.
After not being considerated by Independiente's coach Antonio Mohamed in July 2011 Mancuello was loaned to Club Atlético Belgrano for one year.  On 26 October he scored his first and only goal in a 1-0 victory against Tigre. In January 2012 Mancuello suffered an injury in a match of the Copa Argentina which kept him out of the fields for several weeks when he was being a key player of his team.