Hernaiz, who was placed on the 10-day injured list earlier Wednesday, has been diagnosed with a severe left ankle sprain and will visit with a foot specialist, Martin Gallegos of MLB.com reports.
Hernaiz was injured during Tuesday's 15-8 loss to the Rangers when he stepped awkwardly on first base and was subsequently placed on the IL. More should be known about a potential timetable for the rookie infielder following his exam, but Hernaiz looks as though he could be sidelined for weeks, if not months. The 22-year-old has slashed .182/.243/.182 over 75 plate appearances with Oakland this season and had recently been serving as the team's everyday shortstop.