Junior Guerra will start Tuesday for the Milwaukee Brewers, who designated left-handed relief pitcher Sam Freeman to Triple-A Colorado Springs on Monday.
Guerra appeared in three games in 2015 for the Chicago White Sox, allowing seven hits and three earned runs in four innings. The 31-year-old is 0-2 with a 4.63 ERA in four stats this year for Colorado Springs, allowing 12 earned runs and striking out 23 batters in 23 1/3 innings. He allowed five runs in five innings in his most recent start on April 25.
A right-handed pitcher, Guerra has a career 6-15 minor-league record and 3.97 ERA for 11 teams since 2006.
The 28-year-old Freeman has allowed 11 earned runs in 7 2/3 innings this year.