Then, he returned to Argentina to play for his first club Gimnasia y Esgrima de La Plata, which was struggling to keep its Primera A standing.

Sosa was unable to deliver on his promise to score twice against derby rivals Estudiantes,[3] and became upset with those who criticized him for running his mouth, citing his ten-year playing spell in Europe.

[7] He then served as head coach of Eccellenza Campania club Savoia throughout the 2015–16 season, ended in third place.

In September 2016, Sosa accepted an offer from newly promoted Serie D club Vultur Rionero.

Sosa's son Tomás, born 2001 in Udine, followed on his father's footsteps and he plays for Serie C club Pontedera as of February 2023.