Walker is out of the lineup for Wednesday's game against the Rays.
Wilmer Flores will man first base in the series finale while Walker heads to the bench following a stretch of 14 consecutive starts. Though the 28-year-old has been a pleasant surprise for the Diamondbacks this season and maintains an excellent .943 OPS on the season, he's currently stuck in a bit of a home-run drought. He hasn't cleared the fence since April 23, though he has at least racked up eight doubles over that stretch.