Brewers manager Ken Macha said Braun's back tightened over the course of Friday night's 5-2 loss to Arizona. Braun went 1-for-4 in the game, singling in the first inning and is hitting .314 with five homers and 16 RBI this season.
Macha said he would wait until gametime to decide if Braun would be available to pinch hit and replaced him in the lineup with Chris Duffy.
The Brewers also gave shortstop J.J. Hardy a second day off because of his continued struggles at the plate. Hardy has been off to a poor start this season, batting .156 with one hit in his last 20 at-bats.