Peralta and the Brewers won't play against the Cubs on Monday after the game was postponed due to inclement weather, Todd Rosiak of the Milwaukee Journal Sentinel reports.
Peralta will get an extra day of rest prior to pitching the first game in Tuesday's doubleheader, while Aaron Ashby will start Game 2. The righty has been effective recently with a 1.13 ERA and 0.88 WHIP in 16 innings across his last three starts.