Gillaspie attended Millard North High School in Omaha, Nebraska, where he played baseball, football, and basketball.

[1] On the strength of a recommendation from umpire and fellow Nebraskan Bill McGuire, Gillaspie was recruited to play baseball at Wichita State.

[9] Gillaspie began 2012 with Triple-A Fresno, hitting .362 with 3 HR and 13 RBI in 23 games before being recalled to San Francisco when Pablo Sandoval was placed on the 15-day DL.

On February 22, 2013, the San Francisco Giants traded Gillaspie to the Chicago White Sox for minor-league pitcher Jeff Soptic.

[15] In February 2016, the San Francisco Giants signed Gillaspie to a minor league deal with an invitation to spring training.

On August 6, he cleared waivers and returned to the organization to play for the Giants' Triple-A affiliate Sacramento River Cats.