The 2012 offensive rookie of the year told reporters: "The knee feels fine. I'm not sure which defensive tackle it was came in and landed all 300-plus pounds of himself on my leg. I think it just really scared me.
"After I got up and the doctors checked me I was fine, ready to back in the game, talked with [head coach] Mike [Shanahan]. Just the way the game had gone and Kirk [Cousins] was already out there, it was just smart to keep me off the field and just be ready to go next week.
"We all made a decision that I was fine, I could go back in the game and then we all made the decision that it was time to keep me out at that point."
Griffin missed the entire pre-season while recovering from surgery to repair ligaments in his right knee.