Peterson is out of the lineup for Monday's game against the Giants.
He's one of several lefty-hitting regulars in the Milwaukee lineup with southpaw Sam Long on the hill for San Francisco. The righty-hitting Mike Brosseau will step in for Peterson at third base Monday, but both players will see their opportunities to play the hot corner take a hit in the likely event that Luis Urias (quadriceps) returns from the injured list later this week.