'SNL' star Pete Davidson is sticking to his guns in his beef with the NFL's weed policy ... saying the league suspending a player for using marijuana to deal with his Crohn's disease is "terrible."
The player Davidson's talking about is Buffalo Bills lineman Seantrel Henderson ... who was hit with a 10 game ban after a 2nd violation of the league's substance abuse policy earlier this year.
Henderson suffers from Crohn's -- a painful, chronic, disease of the digestive tract -- and has argued that he needs pot to manage the pain associated with the condition.
We got Davidson -- who also suffers from Crohn's -- out in L.A. and he told our guy the NFL needs to understand there are strains of medical weed STRICTLY for therapy ... meaning it's not all about getting high.