The Athletics optioned Harris to Triple-A Las Vegas on Friday.
Harris came up from the minors May 3 in hopes of landing a starting job at third base for the A's, but he will now return to Las Vegas after slashing .116/.291/.326 through 55 plate appearances to begin his MLB career. The 25-year-old infielder was finding consistent success in Triple-A before getting called up, and it's still possible he enjoys another stint with the big-league club if his bat returns to form with the Aviators. Miguel Andujar (knee) was activated off the injured list Friday to take Harris' roster spot.