Initially a right fullback who converted to the midfield during the prime years of his career, López made his debut at age 19 with UNAM in 1993.

[1] By the following year he was a starter in defense alongside players such as Claudio Suárez and went on to make 238[1] appearances for the club, but the middle and late 1990s were generally disappointing for Pumas.

There he spent the most productive seasons of his career, moving into a three-man central midfield that also included Rafael García and playmaker Antonio Naelson.

López departed Toluca in 2010 and spent his last top-flight seasons with Cruz Azul, Necaxa, Estudiantes Tecos, and Querétaro.

[4] López was on the preliminary list of players nominated for the World Cup squad, but he was one of three final cuts announced by coach Ricardo Antonio Lavolpe before the tournament.