Former UGA LB/S recently tested positive for a banned substance (i.e., estrogen blocker) and will miss the first 4 games of the 2018 NFL season:
http://www.nfl.com/news/story/0ap3000000925466/article/thomas-davis-violates-ped-policy-will-miss-four-games
http://www.nfl.com/news/story/0ap3000000925466/article/thomas-davis-violates-ped-policy-will-miss-four-games