Manager Craig Counsell said the club hopes Yelich won't be out long term, Haudricourt notes.
Yelich hasn't played since April 11 against the St. Louis Cardinals when he was removed with back tightness. He's missed five straight games.
Through nine contests this season, Yelich was hitting .333/.459/.367 with a pair of stolen bases.
With the slugger joining center fielder Lorenzo Cain on the IL, the Brewers appear likely to continue deploying an outfield of Jackie Bradley Jr., Avisail Garcia, and Billy McKinney. Second baseman Kolten Wong is also sidelined.
"The number of guys we've lost right now from an offensive perspective is definitely significant," Counsell said, according to Haudricourt. "It does change your offense, there's no question about it. Hopefully it's a short-term thing and they're back in there soon."
A corresponding move hasn't been announced yet.