The Brewers exercised Peralta's $8 million club option for 2025 on Saturday, Jon Heyman of the New York Post reports.
Peralta will start Game 1 of the wild-card series for the Brewers on Tuesday, Stephen Watson of Bally Sports Wisconsin reports.
Peralta (10-8) allowed three runs on seven hits and two walks over 4.2 innings Sunday, striking out four and taking a loss against Colorado.
Peralta did not factor into the decision in a loss to the Dodgers on Saturday, allowing three runs on four hits and three walks over four innings while striking out four.
Peralta (6-4) picked up the win Sunday against the Cubs, allowing one earned run on two hits and two walks while striking out eight over seven innings.
Peralta is scheduled to start Saturday against the Tigers, Sophia Minnaert of Bally Sports Wisconsin reports.
Peralta didn't factor into the decision Tuesday against the Cubs, allowing one run on three hits and two walks across 5.2 innings. He struck out 11.
Peralta (3-2) allowed five runs on eight hits and a walk over five innings Friday, striking out six and taking a loss against Houston.
Peralta was reinstated from his five-game suspension and will start Saturday's game against the Cardinals in Milwaukee.
Peralta began serving his five-game suspension for intentionally throwing at Ray's Jose Siri on April 30.