In a corresponding move, catcher Juan Centeno was optioned to Triple-A Colorado Springs.
Prior to suffering the injury, Lucroy recorded only six hits in 45 plate appearances.
Last season the 28-year-old batted 301/.373/.465 with 13 home runs, 53 doubles and 69 RBI and finished fourth in the National League MVP voting.
Milwaukee currently sits in last place in the NL Central with a 17-34 record. The Brewers open a three-game series at St. Louis on Monday.