Sandoval spent seven seasons in the Minor Leagues with the Chicago White Sox and Colorado Rockies organizations before signing with the Philadelphia Phillies in November 2013.

He started 2005 at Triple-A Scranton/Wilkes-Barre Red Barons and was promoted to replace Geoff Geary after the All-Star Game.

Along with Bobby Abreu, Ugueth Urbina, Tomás Pérez, and Endy Chávez, Sandoval became the fifth Venezuelan player on the Phillies roster.

He then fought for a spot on the Phillies roster during the 2006 spring training, but was demoted after the team kept both Alex Gonzalez and Abraham Núñez.

In 2008, Sandoval played in the Cleveland Indians and Toronto Blue Jays minor league systems.