Boston, MA -- (Sports Network) - The Brewers optioned left-handed reliever Mitch Stetter to Triple-A Nashville on Friday, replacing him on the roster with fellow lefty Zach Jackson prior to Milwaukee's three-game interleague set with the Boston Red Sox.

Stetter, 27, is 1-1 with a 3.09 earned run average in 13 appearances for the Brewers this season, but has struggled with his control lately. He has walked 11 in 11 2/3 innings this season.

Jackson, who turned 25 on Tuesday, has not pitched in the big leagues since 2006, when he went 2-2 with a 5.40 earned run average in eight games -- seven starts -- for the Brewers. He moved to the bullpen at Nashville this season, and will be a reliever for the Brewers.