Farrell was recalled from Triple-A Iowa on Tuesday, Mark Gonzales of the Chicago Tribune reports.
Farrell was demoted following Saturday's spot start, but returns to the Cubs with Kris Bryant (shoulder) and Justin Hancock (shoulder) landing on the disabled list. Outside of Saturday's rough start, the 27-year-old allowed three runs (two earned) with 17 strikeouts over 11.2 innings during his recent stint in the majors.