The Cubs signed Fleming to a minor-league contract Monday, Lance Brozdowski of the Marquee Sports Network reports.
Fleming made one relief appearance for the Blue Jays earlier this season and held a 3.08 ERA and 51:11 K:BB over 64.1 frames with Triple-A Buffalo. He was released Sunday after exercising an opt-out clause in his minor-league deal. The Cubs' pitching staff has been decimated by injuries, so Fleming could get an opportunity with the big club sooner rather than later.