Randy Gregory tested positive for marijuana at the scouting combine in February.

Gregory is a potential top-10 pick in the 2015 NFL Draft at outside linebacker.

Gregory, who starred at defensive end for Nebraska the past two seasons, admitted he has a lengthy history with marijuana, saying he began smoking after graduating from high school. He tested positive for the drug in January 2014 and April 2014 at Nebraska, according to the NFL.com report, and faced being kicked off the team had he failed a third test.

The positive test could send Gregory down draft charts. In their latest mock drafts, ESPN's Mel Kiper Jr. had Gregory going seventh overall to the Chicago Bears, while ESPN's Todd McShay had him going fifth to the Washington Redskins. McShay also ranked Gregory as the top outside linebacker in the draft.