The Athletics optioned Hernaiz to Triple-A Las Vegas on Saturday.
Both Hernaiz and Joey Meneses will head down to Triple-A in moves that correspond with the Athletics selecting Brian Serven's contract from Las Vegas and reinstating Zack Gelof (hand) from the 10-day injured list. Hernaiz did not see major-league action since being called up by the Athletics this past Monday but will see more playing time in Triple-A, where he has a .714 OPS with two steals and six RBI over 82 plate appearances.