Peterson is out of the lineup for Thursday's game against the Pirates.
The lefty-hitting Peterson will sit for the second straight day and the third time in four games with a southpaw (Jose Quintana) toeing the rubber for Pittsburgh. Platoon mate Mike Brosseau replaces Peterson at third base, though both players are expected to see their opportunities take a big hit in the near future with Luis Urias (quadriceps) potentially set to make his return from the injured list this weekend or early next week.