Gausman last pitched for the Blue Jays on Saturday before being dealt to the Windy City for prospects Brett Bateman and Ty Southisene late Sunday night.
Had the 35-year-old remained on turn, his next outing would have lined up to come on Thursday, when the Cubs and Blue Jays are set to square off in a make-up game from a rainout in June.
If Chicago stays on its original rotation schedule, David Peterson will pitch for Chicago in that afternoon contest. Toronto manager John Schneider said Tuesday that Dylan Cease will be starting for the Blue Jays on the North Side.
The veteran Gausman made 23 starts for the Blue Jays this season before the trade, recording a 4.38 ERA and racking up 127 strikeouts.
On Tuesday, he took to social media to thank Toronto for the last four-and-a-half seasons.
“Toronto, so many great memories with amazing people that I will cherish forever!” Gausman wrote. “Getting to represent an entire country was truly an honour that I never took for granted! Love you all!