Career
Early years
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. Loan to Belgrano
After not being considered 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 Return to Independiente
Flamengo
On January 6, 2016 Mancuello was signed by Brazilian club Clube de Regatas do Flamengo for a fee of R$ 12 millon.
On March 20, 2015 Mancuello was called up by Argentine coach Gerardo Martino for the friendly matches against El Salvador on March 28 and Ecuador on March 31, 2015. He made his debut against El Salvador at Fedex Field, replacing Ángel Di María in the second half and scoring a debut goal from a free kick at the end of the match.
In May he was selected for the preliminary squad for the 2015 Copa América but he wasn"t considered for the definitve draft.