Head coach Kevin Stefanski said after the 37-34 win over the Bengals that Beckham will go for an MRI as doctors evaluate the extent of the damage to his knee. There was no discussion about any initial diagnosis, but Ian Rapoport of NFL Media reports that early indications are that he suffered a major injury.
Beckham was injured while trying to make a tackle after an interception. He did not have a catch before exiting the game.
Beckham did not miss a game for the Browns last season, but it appears that the best case scenario is that he’s just out for most of the rest of this season.