Montgomery (hamstring) was placed on injured reserve Saturday, Mike Triplett of ESPN.com reports.
Montgomery was a surprise entry on the injury report Friday, earning a questionable designation for Sunday's contest with the Packers. A revenge matchup with his former team will have to wait for another day as the Saints made the surprising choice to put Montgomery on injured reserve the following day. The scatback will be out a minimum of three weeks, leaving Alvin Kamara and Latavius Murray to shoulder the burden of an offense absent star wideout Michael Thomas (ankle).