If you were injured on the job and your company did not get involved immediately, I gather that it is maybe an on going injury you're talking about, like carpal tunnel, not a sudden oopsie type injury such as that you fell off a ladder or something. In most states, even if you show evidence of marijuana use when you are tested, (which is usually done in case of a work related accident) if the injury was not directly related to the drug use, they'll still cover things, and it would be decided on a case by case basis.