We need him against the Vikings, that is a winnable game. Their offense is stoppable and we can outperform their defense, but I doubt we do that without Griffin. I think we might have won this game with Griffin in the game instead of Captain Kirk Staredown (I kid, I don't blame a 4th round rookie for failing in that situation even if he did play bad).
That being said, don't rush him back in if he is not ready, brain injuries are very serious obviously and his safety is more important. I just hope he is okay, I think this serves as a wake up call for the coaches and training staff, not to mention Griffin himself.