Farrell was sent down to Triple-A Iowa on Monday, Sahadev Sharma of The Athletic Chicago reports.
The Cubs' pen was taxed after back-to-back extra-inning games over the weekend. Farrell himself was quite busy, earning the win Saturday but taking the loss Sunday. His ERA sits at 7.94 through 5.2 innings, largely due to the three home runs he allowed as his strikeout and walk rates (32.1 percent and 3.6 percent, respectively) were both excellent in his small sample. Cory Mazzoni was promoted to take his spot in the bullpen.