Early years / Zaragoza
Born in Valentín Alsina, Buenos Aires, López began his career with local Club Atlético Independiente in 1991. He won four major titles during his spell there, all arriving in his last years.
In January 1996, López moved to Spain with Real Zaragoza for a club record 420 million pesetas, making his La Liga debut on the 7th in a 1–1 home draw against Rayo Vallecano. He scored five goals in 32 games in his third full season, helping to the ninth position in the table; during most of his stint in Aragon, he partnered countryman Kily González.
López rejoined former Zaragoza manager Víctor Fernández at Celta de Vigo in summer 1999, and quickly became an essential first-team unit. He netted twice in five appearances in the 2000–01 edition of the Copa del Rey, helping the side to the final against his former club (1–3 loss in Seville), then contributed with 33 matches (29 starts, 2.232 minutes of action) in the 2002–03 campaign as the Galicians finished fourth and qualified for the UEFA Champions League for the first time in their history.
At the end of 2006–07, after having suffered his second relegation with Celta and having already renewed his contract twice by reducing his wages, 34-year-old López decided to leave the club, amassing official totals of 292 games and 29 goals. He retired at the end of the following season, also dropping down a level with Cádiz CF in Segunda División, then worked as commentator for Canal+ on their coverage of La Liga and for PRISA regarding the Argentine top level, as well as running training camps for children.