Right fielder Corey Hart needs surgery on his right knee that will sideline him for up to a month.
About 15 minutes before the Brewers' spring training opener, the club scratched Hart from the lineup because of swelling in his right knee. He went for an MRI that revealed the tear.
The Brewers said he'll miss three to four weeks.
Assistant GM Gord Ash said Hart has had ongoing knee issues but that it's never been this bad.
Hart hit .285 with 26 homers and 63 RBIs last season, when he hit leadoff during Rickie Weeks' prolonged absence from the lineup. Two years ago, he went deep 31 times and drove in 102 runs.
Weeks was a late scratch Sunday with right shoulder tightness.