The Cubs recalled Roberts from Triple-A Iowa on Tuesday, Meghan Montemurro of the Chicago Tribune reports.
The Cubs traded Mark Leiter to the Yankees on Tuesday, so Roberts will now come up from the minors to fill the open spot in Chicago's bullpen. The 27-year-old hasn't allowed a run in six MLB innings this season, though he has surrendered three earned runs in three frames since returning to Triple-A earlier this month.