The Cubs optioned Palencia to Triple-A Iowa on Wednesday, Taylor McGregor of Marquee Sports Network reports.
One of six relievers who worked in Tuesday's 12-11 loss to Arizona, Palencia will be swapped off the 26-man active roster for a fresh bullpen arm in Hayden Wesneski, who was recalled from Iowa in a corresponding move. Palencia had given up at least one run in each of his three relief appearances for Chicago this season and posted a 5:7 K:BB over six innings.