The Cubs selected Stout's contract from Triple-A Iowa on Monday.
The addition of Stout gives the Cubs a fresh left-handed arm out of the bullpen after southpaw Sean Newcomb was designated for assignment in a corresponding move one day after serving up five runs in an inning of relief in an 18-4 loss to the Yankees. Stout's lone previous big-league experience came in 2018 as a member of the Royals, with whom he pitched 2.1 innings while giving up six earned runs. The 29-year-old turned in a 3.99 ERA, 1.37 WHIP and 47:22 K:BB across 29.1 innings at Iowa this season.