The move is retroactive to last Saturday. It comes one day after the 28-year-old left-hander was scratched from his start at Detroit.
Reliever Carlos Villanueva got the start in his place and pitched five strong innings but received a no-decision in the Brewers' 3-to-2 win yesterday.
Capuano was replaced on the roster by starting pitcher Yovani Gallardo. The rookie could make his major league debut Monday at home against Barry Bonds and the San Francisco Giants.
The 21-year-old Gallardo went 8-and-3 with a 2-point-9-oh E-R-A in 13 starts at Triple-A Nashville this season. The right-hander led the minors with 110 strikeouts in 77-point-2 innings, as opponents batted .189 against him.
He was named the Brewers Minor League Pitcher of the Year in 2006.