I can see why, with NBA. Long schedule, lotsa travel and videogames in hotel rooms. But NFL is more surprise. Plus, it's likely a PED for NBA (calming), while NFL you don't need that.
http://profootballtalk.nbcsports.com/2018/04/20/marijuana-testing-period-opens-today-4-20/Former NBA player Kenyon Martin, believes that “85% of the league” smoked weed when he played. The former Nugget made the comments in a recent interview with Bleacher Report. Martin’s interview comes on the heels of a podcast interview where former Patriot Martellus Bennett estimated the NFL’s weed use at “about 89%.”