Potential medical benefits of marijuana are discussed for NFL players. https://www.youtube.com/watch?v=dUV9xKKzEHM
I have persoanlly smoked pot with professional sports athletes. In the off season of course. Don't think they aren't smokin it
A NFL team's doctor is prescribing all sorts of opiates sand semi-legal steroids all the time all in an effort to keep the player on the field. Weed is pretty tame compared to those. And it's not performance enhancing. It's not like smoking a joint will make you throw 10 yards farther. I don't see why you would not allow it.
If anybody has a "need for weed", NFL players likely do. probably minimizes the mental and physical effects of hits, strains, etc.