MLB teams learned a few days ago that Oklahoma right-hander Jonathan Gray tested positive for the banned stimulant Adderall during the league's mandatory drug testing for the top 200 prospects in each draft class (as determined by MLB's internal scouting bureau). Because many current big leaguers use the drug after gaining therapeutic use exemptions (TUEs) from the league, Gray's test results aren't likely to significantly affect his draft stock, although there could be some subtle ripple effects.