Cameron reported Monday with symptoms and was placed in the testing program immediately, Browns coach Rob Chudzinski said.
Cameron evidently was injured at some point during Sunday's 38-31 loss to the Chicago Bears. He played the entire game and answered questions coherently when interviewed after the game in the locker room.
Symptoms can be delayed, though, and evidently they were with Cameron.
Browns cornerback Joe Haden did not practice Wednesday due to his bruised hip and is considered day to day, Chudzinski said.
Running back Willis McGahee returned to practice and is cleared to face the Jets after missing the Bears game with a concussion.