Braun had missed the last six games with the injury. Since the outfielder hadn't played, the move was made retroactive to April 27 and he will be eligible to return on May 12.
Braun also had been sidelined a few games this season by a sore right thumb. Overall, the former NL MVP is batting .318 with six homers and 18 RBIs.
Milwaukee activated outfielder Logan Schafer off the disabled list before a game against the Cincinnati Reds. He'd been sidelined by a strained right hamstring.
The Brewers had the best record in the majors when they made the moves. They were hopeful that Braun could be back in less than two weeks, but finally decided it was better not to rush him.
"I think for a lot of reasons it makes the most sense - for me, for the team, just looking out from a long-term perspective," Braun said. "It made more sense to try to let it get healthy instead of trying to force it and rush back.
"We're headed in the right direction. If we weren't headed in the right direction, we would have made the move immediately. But it's definitely gotten better. The oblique is one of those trick injuries."
Braun went on the disabled list for the first time in his career last season, sidelined from June 14 to July 7 with an injured right thumb. He accepted a 65-game suspension on July 22 for violations of Major League Baseball's drug agreement and labor contract.
Shortstop Jean Segura and third baseman Aramis Ramirez also missed time with injuries last week. Despite the setbacks, Milwaukee took a 21-9 record into Saturday night's game.
With Braun sidelined, the Brewers have been short-handed in the outfield. First baseman Mark Reynolds made his first career start in right field on Thursday night. Schafer batted .214 with two RBIs before he got hurt.
Manager Ron Roenicke expects Braun to be fully recovered from the injury when he's eligible to be activated.
"This way hopefully we will be assured that it will be gone when he's back," Roenicke said. "So it makes sense to do it."