Njoku entered the locker room with medical staff during the first quarter of Monday's game against the Jets, Nate Ulrich of the Akron Beacon Journal reports.
Njoku attempted to make a catch on the Browns' second drive and was upended, resulting in an awkward fall on his head and neck. Demetrius Harris, Pharaoh Brown and Ricky Seals-Jones are slotted to compensate for Njoku's absence as long as he is out.