Mar 26, 2015 3 min read

Defensive end Randy Gregory said he tested positive for marijuana at the NFL scouting combine last month and that he failed two drug tests at Nebraska last year.

Gregory disclosed his marijuana use in an interview with NFL Media on Wednesday.

Gregory went into February’s scouting combine projected to be among the top 10 picks in the draft. He declared for the draft after his junior season at Nebraska, where he recorded 17 1/2 sacks in two seasons.

He said he tested positive for marijuana at Nebraska in January 2014 and April 2014. Gregory said he hadn’t smoked marijuana since December.

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

Eddie Rhodman Jr., one of Gregory’s handlers, said on Thursday that Gregory would not comment further.

Gregory said he knows the failed drug tests could hurt his draft position.

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

Gregory, from Fishers, Indiana, played his freshman season at Arizona Western Community College in 2011 and missed 2012 because of a broken leg. He transferred to Nebraska in 2013.

Gregory missed two games because of injury last year but was not suspended for any after testing positive twice at Nebraska.

49ers cut Martin: The San Francisco 49ers have waived offensive lineman Jonathan Martin.

The team announced the move on Thursday to end Martin’s one-year trial run with the team.

The Niners acquired Martin last March in a deal with Miami. Martin had left the Dolphins in October 2013 after accusing teammate Richie Incognito of bullying. An NFL investigation determined Incognito and two other Dolphins offensive linemen engaged in persistent harassment of Martin.

Martin started seven games at right tackle last season in place of injured Anthony Davis. He struggled in that role and allowed 7 1/2 sacks, according to STATS.

Dolphins sign Shelby: Miami Dolphins defensive lineman Derrick Shelby has signed his restricted tender offer and will make $2.4 million this year.

Shelby, who signed Thursday, provides depth in a front four upgraded with the recent signing of tackle Ndamukong Suh.

Shelby, a three-year veteran, saw significant playing time off the bench last year at both tackle and end. He had 21 tackles and three sacks.

Bengals sign DT: The Bengals brought back defensive tackle Pat Sims on Thursday, signing him as an unrestricted free agent from Oakland.

Sims was Cincinnati’s third-round pick in 2008 and spent five seasons with the Bengals before leaving as a free agent. He spent the last two seasons with the Raiders, playing in 32 games with a total of 85 tackles. He has seven career sacks and one interception.