Human Resources

I have a supervisor how recently informed me that he has a worker that he believes is using drugs. He said he has spoken to the worker on two separate occasions about keeping “extracurricular activities” to the weekends and not while he is at work. We are a member of the TN Drug Free Workplace which gives us the freedom to pre-screen, random screen, and screen on suspicion. But, I am not finding a clear happy definition of what suspicion is. I told my supervisor that the next time he feels the need to speak to this worker again just send him to be screened. Medical topics seem to be such hot topics right now that this makes me nervous. Am I good with my recommendation to my supervisor?