He suffered a ruptured right Achilles tendon while running out a grounder in the 2002 American League Division Series against Minnesota and was sidelined for the remainder of the post season and most of 2003.

A question mark because of his injury history, Sáenz was not retained by the A's and wound up attending spring training with the Los Angeles Dodgers as a non-roster invitee, earning a spot on their roster as the primary right-handed pinch hitter.

He was part of Major League history when, on September 8, 2004, he hit a pinch-hit grand slam homer, marking the first time in MLB history that a team had a pinch-hit grand slam in back-to-back games, as Robin Ventura hit one on September 7.

Sáenz became well known as being a dead fastball hitter, a skill upon which Vin Scully remarked at virtually every one of Saenz's plate appearances.

[2] On February 12, 2008, Sáenz signed a minor league deal with the New York Mets and was invited to spring training.