The Athletics optioned Hernaiz to Triple-A Las Vegas following Sunday's 4-3 win over the Brewers.
Hernaiz's demotion clears room on the roster for fellow infielder Jacob Wilson (hamstring), who appears set to return from the 10-day injured list ahead of the Athletics' next game Tuesday in Cincinnati. Since being activated from the 60-day IL earlier this month, Hernaiz had settled in as the Athletics' primary option at third base, but he slashed just .209/.306/.326 with three extra-base hits and no stolen bases over 15 games to earn a trip back to Triple-A. With Wilson likely to take over as the Athletics' everyday shortstop, Max Schuemann is expected to slide over from shortstop to replace Hernaiz at third base.