Stewart last pitched in the majors in 2019, going 2-2 with a 6.39 ERA in nine appearances with Minnesota. The 26-year-old Stewart signed with Baltimore in December 2019, but never played for the Orioles.
Stewart's deal with Chicago is worth $700,000 while he is in the majors and $150,000 while he is in the minors.
The 6-foot-3 Stewart was selected by the Twins with the fourth-overall pick in the 2013 amateur draft. He is 4-3 with a 4.79 ERA in 17 career games, including six starts.