He spent most of his professional career with San Lorenzo, Racing Club and AEK Athens, being one of the most prolific goal-scoring goalkeepers in history.

Born in La Plata, Buenos Aires Province, Saja had nearly 200 overall appearances for San Lorenzo de Almagro, being voted South America's best goalkeeper in 2002.

He appeared in 29 games in his first year to help his team finish fourth in the league, but they was also quickly eliminated from UEFA Cup contention.

[8] On 9 June 2013, again from the penalty spot, Saja scored against Boca Juniors (2–0 home triumph, which qualified the team for the Copa Sudamericana).

[10] On 16 August 2016, free agent Saja signed a one-year deal with Gimnàstic de Tarragona, returning to Spain and its second tier after 11 years.