Potential sliders in the 2015 NFL draft

There's no doubt that some prospects, many of whom are dealing with off-field issues, will be selected after their projected draft pick.

Inevitably, in every NFL draft, there's that one prospect who expects to be a top pick, but then watches as his stock falls like an anvil dropped off a tall building. This generally occurs while cameras are pointed at him from every angle in the green room, waiting to capture his growing sense of discouragement. 

Shane Ray, La'el Collins questions hang over NFL draft festivities

We all remember how Aaron Rodgers looked as he fell... and fell... and fell... in the 2005 draft, eventually going No. 24 overall to the Packers, while Alex Smith went first overall the 49ers, Rodgers' favorite team at the time. It's safe to say that things worked out better for Rodgers than they have for Smith, and there are teams certainly kicking themselves for passing on who may be the NFL's best quarterback right now. Think of the Vikings—they had two first-round picks before Rodgers was taken, and they selected Troy Williamson and Erasmus James. To add insult to injury, they get to face Rodgers twice a year. How'd that work out?

Most draft sliders don't have those kinds of success stories, though, and the divide between popular perception and league reality when it comes to how prospects are valued can be pretty harsh. Whether it's due to injuries, off-field issues or a general feeling that, "Hey, this guy just isn't as good as we thought," the reasons can come from just about anywhere. Here, and for multiple reasons, are the players who could start to plummet down the boards as the 2015 NFL draft gets underway.

• ​KING: Who will every team draft? | BEDARD: Who should every team draft?

Shane Ray, DE, Missouri

Packed with upside: Most overrated prospects in 2015 NFL draft

In a vacuum, Ray is rightfully regarded as one of the best pure pass-rushers in this draft class. At 6'3" and 245 pounds, he's got an amazing first step, ability to bend the edge, and potential to close on the quarterback in a big hurry. He was the SEC Defensive Player of the Year in 2014, leading the conference with 14.5 sacks and finishing his final collegiate campaign with 22.5 tackles for loss. It was bad enough when Ray's foot injury prevented him from working out at the combine, but teams will overlook such things for talent. After all, Ray did all the drills at his pro day in March. The team that takes him knows the foot issue is a potential tripwire, but teams take those risks all the time.

But when Ray was pulled over early Monday morning for a traffic violation and was cited for possession of marijuana, all hell broke loose in the media—and perhaps justifiably so. The possession of marijuana itself isn't a big deal these days to most people, but the fact that Ray was caught carrying the week of the draft, especially when he already has one failed drug test on his record, will resonate with teams. Front offices will see this as less a failed drug test and more a failed intelligence test. ESPN analyst and former Buccaneers general manager Mark Dominik said Tuesday that he wouldn't be surprised if this news knocked Ray into the third round. Falcons head coach Dan Quinn has said that Ray is still on his team's draft board, but it'd be tough to expect Ray to go with the eighth overall pick (where Atlanta currently stands) or anywhere close.

• BANKS: The Wes Welker Watch List: Top potential undrafted free agents

Randy Gregory, DE/OLB, Nebraska

There were enough questions about Gregory before he failed a drug test at the combine, testing positive for marijuana at the most important job interview he'll ever have. Some teams wonder how well Gregory will hold up against NFL blockers at 235 pounds, but the failed test was more about timing than substance. In addition, some in the league believe that Gregory doesn't hold himself responsible for his travails, and while that might be a smokescreen, it's not good news for him in a very deep class of pass-rushers.

Marcus Peters, CB, Washington

Packed with upside: Most overrated prospects in 2015 NFL draft

Peters was booted off the Huskies squad last November after clashing with the new coaching staff, led by head coach Chris Petersen. He returned home to Oakland to try to get his life in order, and eventually apologized to Peterson and his staff for his tantrums. Peters's apology led to an invite to Washington's pro day in early April, andnd at that pro day, Peters didn't look like a guy who hadn't played in months—he was as quick and agile as you'd expect. That performance was a victory, but there are those who are concerned about Peters's thought process. There's a lot of talent in this cornerback class, and though it could be argued that Peters is the best at the position overall, he could find his top-15 talent sliding into the back half of the first round.

• VRENTAS: Todd Gurley's draft stock is climbing amid his recovery

La'el Collins, OT, LSU

Collins was thought to be a sure-fire first-round pick, with many analysts putting him just below Iowa's Brandon Scherff as the second-best offensive linemen in this class. But on Wednesday, the story broke that police sought to speak with Collins in the shooting death of 29-year old Brittany Mills. It's important to note that Collins is not a suspect in the shooting—merely a person of interest for questioning—because Mills is believed to be a former girlfriend of Collins's. Collins left the draft in Chicago to speak with police, and multiple reports indicate that several NFL teams have taken him off their boards until more can be learned. This is obviously a sensitive and developing story, but that's what we know at this time.

T.J. Clemmings, OT, Pittsburgh

2015 NFL Draft All-Underrated Team

​Clemmings was a defensive lineman his first three years for the Panthers before switching to right tackle before the 2013 season, and as you might expect with just two years experience, he's got some technique work to do. However, and as the tape shows, Clemmings may have as much potential as any offensive lineman that will come off the board this week—he's quick and powerful, and he'll just dominate defenders at times. But as Ian Rapoport of the NFL Network first reported, Clemmings has been dinged by some clubs because of a stress fracture in his foot. Clemmings's agent Mike McCartney said that it was an old injury, but there could be a buyer beware that sees Clemmings drop into the early second round.

Jalen Collins, CB, LSU

Collins started just 10 games during his time with the Tigers, but that had little to do with his own talent -- it was more about LSU coach Les Miles's ridiculously deep rosters. When Collins was on the field, he displayed just about every possible attribute you'd want from a top-tier NFL cornerback. At 6'2" and 195 pounds, he runs with speed receivers well and understands coverage concepts better than you might expect from a player with such limited starting experience. But the news that he failed multiple drug tests at LSU could have teams wondering just how much they want to stretch out on a double risk.

Jay Ajayi, RB, Boise State

2015 NFL draft team previews

One of the most prolific rushers in the nation in 2014, Ajayi finished his season with 1,823 yards and 28 carries on an NCAA-leading 347 carries. He looks every bit the picture of a future NFL running back, but as happens with so many at his position, Ajayi's workload could work against him—especially if the alleged concerns about his knee hold up. Ajayi tore his right ACL in 2011, and several legitimate insiders believe the league wonder how durable he'll be, though he wasn't asked to attend the combine's medical re-check. Ajayi is probably a second-round prospect without those issues, but if he slides, that's likely why.

Dorial Green-Beckham, Oklahoma

More than any player on this list, Green-Beckham's NFL future could be determined by the league's trepidation over the past of one player—Cleveland's Josh Gordon. Like Gordon, Green-Beckham was booted off one team (Missouri's), joined another (Oklahoma) and never actually playing for his second school. After he was asked to leave Baylor for failing multiple drug tests and languishing though the 2011 season in Utah, Gordon was selected in the second round of the '12 supplemental draft. He's currently serving an indefinite NFL suspension that will keep him out for at least the 2015 season. Green-Beckham was dismissed by the Missouri program after multiple criminal and drug-related incidents, and the NCAA refused his request to play for Oklahoma after his transfer. Green-Beckham has as much raw talent as any receiver you'll see, but teams will and should be very, very cautious. He's a top 10 talent who could just as easily slip all the way out of the first round.