The Cubs placed Roberts on the 15-day injured list Monday due to right forearm inflammation.
Roberts has allowed five runs (four earned) over his last three appearances out of the Chicago bullpen. His recent struggles may have been linked to the forearm injury, and by going on the 15-day IL, he'll be shelved until at least after the All-Star break in mid-July. Gavin Hollowell was recalled from Triple-A Iowa to give the Cubs more depth out of the bullpen in Roberts' absence.