ESPN.com's Jerry Crasnick first reported the deal Friday. The Brewers will receive minor league outfielder Malik Collymore and will reportedly also send cash considerations to St. Louis, according to MLB.com's Adam McCalvy.
Broxton, 31, holds a 5.89 ERA in 40 appearances this season, striking out 37 batters in 36 2/3 innings. The righthander served as a setup man in Milwaukee but has closing experience, with 118 career saves.
Collymore, a 20-year-old outfielder, has hit .286 with four home runs, 44 RBIs and 12 steals over the past three seasons at the Rookie level. He was the Cardinals' 10th-round pick in the 2013 draft.
- Jeremy Woo