Former Nebraska defensive end Randy Gregory is considered to be one of the top prospects in this year’s NFL Draft. Now, it’s uncertain when he’ll land after testing positive for marijuana use at the NFL Scouting Combine in February.

“I blame myself,” Gregory said NFL Media. “And I know it sounds cliché, but there’s really no one else I can blame.”

Gregory said to NFL Media he found out he failed the test about two weeks ago. He said he thought he had received a letter that was inviting him to the NFL Draft. Instead, it was the news he failed the drug test he took during his time in Indianapolis.

During his time at Nebraska, Gregory tested positive for marijuana twice- both in early 2014. He said he’s been smoking for a few years. According to Gregory, it was an outlet to cope with anxiety after he failed to qualify academically to the Purdue University.

He said he’s going to get past this, and is “in a great spot,” with the NFL Draft coming up on April 30.

“I don’t wake up every day saying, I’d really love to go smoke,” Gregory said. “It’s not a struggle for me every day (now), it really isn’t. In the past, hell yeah, it’s been a struggle. It really has been. Now, I’m focused on my dream.”

Gregory said to NFL Media Kimberly Jones he hasn’t smoked since December. But because of the THC levels, the drug was still in his system when he went to the NFL Scouting Combine.

“I was worse at Nebraska than I’ve ever been at any other time of my life,” Gregory said. “But I know how I am now. I think if teams really look at how I am now more so than the past, they’ll see I’m making strides to get better, as a person and as a player.”

The 6-foot-5, 243-pound lineman said he doesn’t want this incident to define who he is. He had 17.5 sacks in two seasons at Nebraska, which put him in a good position for the NFL Draft. He said he realizes marijuana can ruin a career and that needs to change.

“I don’t want my career to be defined by the fact that I had failed a drug test or anything of that sort,” Gregory said. “I want people to remember me as that top-10, top-five (draft pick) that had a 10-year career, a number of championships. I want to be known as that guy. I don’t want to be known as a bust or that guy who came in (to the league) with a drug habit.”