The Indianapolis Colts placed wide receiver Parris Campbell and safety Malik Hooker on injured reserve Tuesday.
On Monday, coach Frank Reich said Campbell would "miss some time" with a MCL/PCL injury in his left knee.
Campbell will be out at least until Week 6 as a trip to the injured reserve this season lasts a minimum of three weeks.
Hooker is out for the season after suffering a torn Achilles injury in Sunday's win.