https://profootballtalk.nbcsports.co...rs-concussion/

Parker displayed signs of instability while getting to his feet after making a catch and hitting his head on the ground, but was lining up for the next play before the game was stopped because the Cardinals were challenging whether or not he actually made the catch. The review was done to find out why concussion spotters had not stopped the game in order to have Parker evaluated for a head injury.