Born in Trenque Lauquen, Buenos Aires Province, Farías started playing professionally in 1997 for Estudiantes de La Plata, making his Primera División debut in a 2–2 draw against Club Atlético Lanús, 19 days shy of his 18th birthday.

[2][3] He signed with Italian club U.S. Città di Palermo for the 2004–05 campaign, teaming up with compatriot Mariano González and appearing in only 13 Serie A matches, going scoreless in the process.

Subsequently, Farías returned to his country and joined Club Atlético River Plate, being crowned top scorer in the 2006 edition of the Copa Libertadores at five (tied with 13 other players) as the Buenos Aires side reached the quarter-finals.

In January 2010, Farías had everything arranged with Cruzeiro Esporte Clube as part of the deal involving Kléber,[8] but the move eventually collapsed.

In late July he finally joined the Brazilians, agreeing on a three-year contract;[9] he scored his first goal for the club on 5 September, in a 3–2 away win over Sociedade Esportiva Palmeiras.