Jack reverted to the Steelers' practice squad Monday, per the NFL's transaction log.
Jack played 47 of 64 defensive snaps during Saturday's 34-11 victory over the Bengals. His sizeable workload came due to the early departure of Elandon Roberts (pectoral). If Roberts isn't able to suit up for Sunday's road matchup against the Steelers, Jack will stand to be elevated and handle a significant role again.