Stewart was optioned to Triple-A Iowa on Monday, Meghan Montemurro of the Chicago Tribune reports.

EDGE Analysis

The 26-year-old struggled in his second start of the season Saturday versus the Giants with three runs allowed on seven hits over 3.2 innings, and he'll return to the minors with Trevor Williams potentially nearing his return from an appendectomy. Stewart covered five scoreless frames during his first start of the season and could receive another look in Chicago's rotation later in the year.