The Giants placed Pettis (shoulder) on injured reserve Friday, Dan Salomone of the Giants' official site reports.
Pettis suffered a left shoulder injury during Monday's loss to the Chiefs, and he will now have to miss a minimum of three weeks while on IR. If the likes of Kadarius Toney (thumb), Kenny Golladay (knee) and/or Sterling Shepard (quadriceps) are healthy by the time Pettis is able to return, he could see his role on offense significantly reduced.