Nebraska junior pass rusher Randy Gregory tested positive for marijuana at the NFL combine in February.

Gregory is NFLDraftScout.com’s No. 8 overall prospect in the 2015 NFL Draft.

“I blame myself,” Gregory told NFL.com’s Kimberly Jones. “And I know it sounds cliché, but there’s really no one else I can blame.”

Gregory’s past drug use was a concern in league circles before the failed test, dating back to high school and his time at junior college. NFL scouts often point out that marijuana testing at the NFL combine is more of an “idiot test” because every prospect and agent knows about it well ahead of time.

Gregory, who opened eyes in Indianapolis when he weighed at a relatively light 235 pounds, said he hasn’t smoked since December, but it adds another red flag to his already polarizing pro projection.

“Am I worried? Yeah, I’m worried,” he said when asked about his draft stock. “At the same time, I’m confident. I know I’m going to be all right in the end.”

How will this affect his draft stock?

This failed test will be viewed differently by teams as some are more tolerant than others. Kansas City Chiefs pass rusher Justin Houston was thought to be a possible late first-round pick in the 2011 NFL Draft, but after a failed drug test, he slipped to the third round and the No. 70 pick overall. Marijuana hasn’t been an issue for him since entering the league and he has developed into one of the best third-round steals in recent memory.

On the flip side, Cleveland Browns wide receiver Josh Gordon, a second-rounder in the 2012 supplemental draft, looked to be a bargain after leading the league in receiving in 2013. But his constant issues with substance abuse have derailed his career and it’s anyone’s guess when he’ll find the field again, but it won’t be until 2016 at the earliest.

Gregory has top-10 talent, but with concerns about his growth potential and overall reliability because of his past drug use, it wouldn’t be a shock to see him fall past the initial 10 picks.

However, it’s hard to see him falling too far down draft boards and a team picking in the mid-to-late first round might land the Huskers pass rusher at a reduced price.