The move made Monday is retroactive to March 27. Hoffman strained his right oblique muscle after pitching an inning on March 13 and has had little activity for about three weeks.
"You don't want to rush it and set things back," Hoffman said, according to MLB.com. "Just because we're starting to see some progress, you don't want to jump on it to the point you set yourself back two weeks and lose the [progress].
"Two weeks in the middle of the season is going to feel a heck of a lot longer than the last two weeks of spring training, even though this has been frustrating. It would be difficult to watch games go by," he said, according to the Web site.
The 41-year-old Hoffman tossed the baseball around on Sunday but is not ready to take the mound.
"We met with him this morning," Brewers assistant general manager Gord Ash said. "He is feeling much better and has shown much improvement. He has the normal 'day-after' soreness [after pitching]. We did this because we didn't want him to feel he's in a hurry-up mode."
Hoffman signed a $6 million, one-year contract in January with Milwaukee as a free agent after spending more than 15 seasons with the San Diego Padres.
Brewers manager Ken Macha says he will continue to evaluate potential candidates to fill in for Hoffman, who has 554 career saves. The most likely to step in would be right-hander Carlos Villanueva, who had been projected to pitch the eighth inning.
Hoffman is eligible to return on April 11, the day after the Brewers' home opener.
Also, veteran infielder Craig Counsell was in the lineup Monday against the Seattle Mariners after testing his sore right knee the past few days in minor league games. Ash said Counsell faces the possibility of surgery if the knee does not improve. Ash said Counsell has a torn meniscus and surgery would sideline him for two to three weeks.
It's not certain when the injury occurred, but Counsell "tweaked" it recently, Ash said.
Information from The Associated Press was used in this report.