Even with all the attention and scrutiny surrounding the NFL draft, it's still possible for very good prospects to fly under the radar. 

Some are overlooked because of injuries. Others are an inch shorter or a few pounds lighter than the prototype. Some played for small programs or were overshadowed or trapped behind superstar teammates.

So who are this year's best-kept secrets?

The following players project as Day 3 selections, but each has the potential to be much more than roster fodder. These prospects could develop into elusive all-purpose rushers, go-to receivers, three-down linebackers and even a franchise quarterback. 

All they need is an opportunity, plus a little bit of good luck.

Secret Big-Program, Big-Production Sleeper QB: Nic Shimonek, Texas Tech

Nic Shimonek's NFL dream appeared to be dead when the Texas Tech quarterback was benched before his final college game.

"I won't lie to you, I was really ticked off," Shimonek told Bleacher Report about getting benched after a rough outing against TCU.

But Shimonek didn't let negativity get the best of him. "I had seen some guys handle a similar situation in the past a certain way, howling and complaining," he said. "I wasn't a fan of it then, so I didn't want to be that guy. It was almost like being a hypocrite."

So Shimonek mentored his replacement, sophomore McLane Carter, during the week and through three quarters against Texas. But when Carter proved ineffective, Shimonek decided to plead his case to coach Kliff Kingsbury.

"I looked at him and told him that we were almost out of time," Shimonek recalled. "He looked at me like I was crazy. Two minutes later, he sent a graduate assistant to tell me to start warming up. I already had a ball in my hand. I said, 'Shoot, you don't have to tell me twice.'"

The rest is history. Shimonek threw two touchdowns in the fourth quarter to beat Texas. The win made the Red Raiders bowl-eligible. It may have saved Kingsbury's job. It definitely revived Shimonek's NFL hopes.

Shimonek went on to perform well at the East-West Shrine Game. He earned a combine invite, though he was tasked with throwing during running back drills in addition to participating in quarterback drills. Just a few months after benching Shimonek, Kingsbury helped get the Texas Tech pro day rescheduled so his former quarterback wouldn't have to return from a grueling combine week of extra work and immediately prepare for his next big audition.

Doug Farrar broke down film with Shimonek for Bleacher Report a few weeks ago; the feature provides a deep dive into Shimonek's story and his attributes. The short version: Shimonek, who got stuck behind C.J. Beathard at Iowa before transferring and getting stuck behind Patrick Mahomes, has a textbook delivery, NFL-caliber accuracy and the ability to work through a progression of reads. He threw for 3,963 yards and 33 touchdowns last year, three times throwing four touchdown passes in losses in the wide-open Big 12.

Shimonek knows what it's like to wait his turn, overcome adversity and make the most of his chances. Those are three traits that can be more important to a developmental quarterback than his arm.

Projected round: 6th-7th

Potential upside: Case Keenum

Secret Uber-Productive but Overshadowed WR: DaeSean Hamilton, Penn State

DaeSean Hamilton is Penn State's all-time-leading receiver, with more catches than Allen Robinson, O.J. McDuffie, Bobby Engram, Kenny Jackson or anyone else in the program's storied history.

But unless you are a Nittany Lions superfan or hardcore draftnik, you probably haven't heard of him.

"I had an entire career of being somewhat overshadowed," Hamilton told Bleacher Report.

Hamilton caught 82 passes as a freshman, when Christian Hackenberg was Penn State's quarterback. Then Hackenberg left, running back Saquon Barkley became the focal point of the offense and Hamilton was forced to share the dwindling number of passes with Chris Godwn (now a Buccaneers receiver), Mike Gesicki (one of the top tight ends in this class) and others.

"There were a whole bunch of household names," Hamilton said. "I guess I didn't get a chance to be a household name. But I was just worried about getting my job done."

Hamilton's production dipped as the Nittany Lions became Barkley's team. He caught just 34 passes for 506 yards and one touchdown in 2016. But he doesn't blame Barkley or the quarterback change. "I was putting too much pressure on myself to outdo my freshman year and do too much," he said.

Hamilton rebounded with a 53-857-9 stat line as a senior. That led to a Shrine Game invitation, then a call-up to the Senior Bowl, and then finally a 4.47-second 40 at Penn State's pro day.

Hamilton's route running drew praise from former Panthers star Steve Smith during the combine, and his detail-oriented approach, coupled with his size-speed package, have made teams take notice of a receiver who was sometimes lost in the shuffle at Penn State.

"I have a plethora of ways to get open," Hamilton said. "I use a whole lot of different releases. I'm unpredictable in my routes. It's not always going to be the straight line like you would draw on a piece of paper.

"[Penn State receivers coach Josh] Gattis always says that if you do all the details right, the ball will find you."

In Happy Valley, the ball usually found Barkley, no matter what the Penn State receivers did. But after his phenomenal offseason, Hamilton has shown it could find him plenty in the pros. 

Projected round: 3rd

Potential upside: Pierre Garcon

Secret Small of Stature but Big of Heart RB: Phillip Lindsay, Colorado

The first thing that stands out on Phillip Lindsay's game tape is his pass protection. Lots of undersized running backs—Lindsay measured 5'7", 184 pounds at his pro day—can catch passes out of the backfield or put the moves on defenders in the open field. But Lindsay wallops blitzers as if he's three inches taller and 30 pounds heavier.

"I like to block before I run the ball," Lindsay told Bleacher Report. "It gets me going. It establishes the tone of everything. If I can get a good block, I can show the defender it's gonna be a long day. And that can mess their head up."

Lindsay rushed for 2,726 yards and 30 touchdowns in his final two seasons with the Buffaloes, adding 76 receptions. But his pass protection chops and 4.39-second pro day 40 should make NFL evaluators overlook his size and give him a chance to make a roster as an all-purpose mighty mite.

It's a miracle that Lindsay is even in the draft conversation at all. He suffered a major knee injury in the first game of his final high school season. His family couldn't afford post-surgery rehabilitation, so scar tissue developed to the point where Lindsay could barely bend or straighten his leg.

Once Lindsay finally got some top-quality therapy, he made a swift recovery. "I went from not thinking I would ever be able to play to being ready for my first college practice," he said.

A background in taekwondo—Lindsay's father is a teacher and his sisters are black belts—may have sped his recovery. A healing crystal, which Lindsay still wears taped to his ankle on game days, did nothing to slow things down. "I'm a spiritual guy," Lindsay said of his holistic healthcare approach.

Lindsay's nickname is the Tasmanian Devil, and both his running and blocking style live up to the billing. Teams seeking a hard-nosed, Dion Lewis-type at late-round prices won't be disappointed by Lindsay's production—or his attitude.

"You're going to have to battle me the entire game," he said. "Even though I'm of smaller stature, I'm a hard body. I'm strong. And I bring contact."

Projected round: 5th-6th

Potential upside: Dion Lewis

Secret Overlooked-in-FCS, Chip-on-Shoulder LB: Nick Deluca, North Dakota State

Somewhere in Omaha, Nick DeLuca's former youth league football coach still awards a trophy to a junior high player who best exemplifies the team's values.

The award is called The DeLuca.

The values?

"Our saying was 'hardcore to the bone,'" DeLuca told Bleacher Report. "So the award is supposed to embody that statement."

"It's pretty intense stuff," he added with a chuckle.

Ironically, DeLuca wasn't yet hardcore to the bone about football in his tween years. Baseball was his top sport, catcher his best position. "It wasn't until high school that I fell in love with football," he said.

DeLuca recorded 103 tackles and 9.5 sacks as a senior, leading Millard North High School to an undefeated record and a state championship. But major programs still didn't come calling. That turned into a blessing in disguise when DeLuca landed at FCS powerhouse North Dakota State.

Now that Carson Wentz has helped the Eagles reach the Super Bowl, you probably don't need to be convinced that NDSU is much more than an outpost in the football boondocks. DeLuca blossomed for the Bison, reaching the Butkus Award watch list as one of the nation's top linebackers (a rare honor for an FCS player) before suffering a shoulder injury that erased his 2016 season.

"It took a lot for me to have to sit out in 2016," DeLuca said. "But I got to see everything from a different perspective and grew as a player."

DeLuca, who always displayed great play recognition and coverage instincts, became even more of a student of the game during and after the injury. "This season, I didn't have many classes, so I was basically majoring in football. I was up in the offices every day, studying film for hours at a time."

DeLuca's awareness in pass coverage led to seven career interceptions, three of them in the FCS playoffs. He added an interception and other highlights during Senior Bowl practices that drew praise from Mike Mayock for both DeLuca and the NDSU program.

With his injuries behind him, the instincts and study habits to excel in coverage and a hardcore-to-the-bone attitude, DeLuca is an NFL-ready prospect at inside linebacker, thanks in part to a small program that keeps churning out big prospects.

"It's the tradition and the culture," DeLuca said of North Dakota State. "We really pride ourselves on the details and the preparation and some of the other things that other teams might overlook."

Major programs overlooked DeLuca. Will NFL teams make the same mistake?

Projected round: 5th-6th

Potential upside: Vincent Rey

Secret Late-Rising, Draft-Process-Winner WR: Daurice Fountain, Northern Iowa

Lightly recruited out of high school and stuck in an FCS program that changed offensive coordinators every single year, Fountain entered his senior season as a long shot to ever come close to the NFL.

Even after catching 66 passes for 943 yards and 12 touchdowns in his final season, he was still having a hard time catching the NFL's eye.

"I had a scout tell me I went from a potential rookie minicamp invite to a sleeper draft pick," Fountain told Bleacher Report.

Earning the offensive MVP award at the East-West Shrine Game still wasn't enough to land Fountain a spot at the combine. Fountain—who attended high school in Madison, Wisconsin, but got lost in the recruiting shuffle when his hometown university shifted from Brett Bielema to Gary Andersen to Paul Chryst—was told that the combine invitation list was too full to accommodate such a late riser.

Fountain then ran a 4.46-second 40 at his pro day, with a 42.5-inch vertical leap that would have topped all wide receivers at the combine. Suddenly, he's racking up the frequent flyer miles with NFL team visits. "I've been visiting cities I have never been to in my life," he said.

Fountain's leaping ability stands out on his game film: FCS cornerbacks don't stand a chance against him on 50-50 balls. His determination and ability to set up defenders with double moves is also apparent.

Teams hosting Fountain will be looking to determine how well he can absorb an NFL playbook. That's where playing for four different coordinators and six different receiver coaches at Northern Iowa works to Fountain's advantage. He's used to learning a whole new set of plays in practice week and executing them in games that very week.

"It's been a norm for me to learn new plays at a rapid pace, literally at the last minute," he said. "That was one of the advantage I've had during all of these whiteboard sessions."

Fountain is now hearing early Day 3 projections. He's also getting some good advice on coping with the airports-and-whiteboards grind from Northern Iowa's most famous NFL alum: Cardinals running back David Johnson.

"He told me to have fun with it," Fountain said, "because this is a once-in-a-lifetime opportunity."

Now that he's finally getting that opportunity, look for Fountain to make the most of it.

Projected round: Late 3rd to early 4th

Potential upside: Davante Adams

Secret Hoops Player-Turned-Pass-Catching TE: Tyler Conklin, Central Michigan

Conklin caught 42 passes for 560 yards and six touchdowns for the Chippewas in 2016. But after he suffered a Jones fracture to his foot in August before his senior season, he did the one thing no one should ever do when coping with a serious medical condition:

He looked it up on the Internet.

"The only scary part was going on Google and looking at everything possible about Jones fractures and the timeline for them, the re-fracture and players who have had it," Conklin told the Central Michigan website last year.

Luckily, Conklin waited until after he rehabilitated well ahead of schedule to do that brand of research that turns a slight cough into the bubonic plague. And despite the horror stories and a swift return to action just eight weeks after the injury, the worst did not happen; he did not reinjure his foot. Instead, he caught 35 passes for 504 yards and five touchdowns in eight games as a senior, though there were times when he still looked understandably tentative on the game film.

Conklin ran just a 4.8-second 40 at the combine, but 40 times can be misleading. He finished among the top tight ends in most other drills, with a 38-inch vertical leap that ranked second only to Penn State's Mike Gesicki among tight ends.

Conklin started his college career as a basketball player at Northwood University before transferring to Central Michigan after one season. Based on the basketball background and mid-major competition, you may expect Conklin to be another oversized slot receiver with a soft blocking style. But he is one of the best blocking tight ends in this year's class, capable of holding his own against edge-rushers and thumping open-field defenders on screen passes.

But it's Conklin's receiving skills that can turn him into an NFL starter. "I want to be in an offense where it's pass-friendly and they use their tight end in different ways, move them around," Conklin wrote in his draft diary for the Detroit Free Press. "Obviously, I don't want to be in a scheme where I just block all the time. "

Luckily, it's not the 1970s, so those schemes don't exist anymore.

Conklin should be in an NFL training camp less than a year after he was hobbling around on crutches. Remember that the next time you look up a mosquito bite on the internet and think you need to run to the emergency room.

Projected round: 4th

Potential upside: Brent Celek

Other Secrets of the 2018 Draft

A few other players who could get drafted on Day 3 and then make waves:

Richie James, Wide Receiver, Middle Tennessee State: A pint-sized (5'9"), super-productive slot receiver and Wildcat for the Blue Raiders, James caught 212 passes with 20 touchdowns in 2015-16 before suffering multiple injuries in 2017. The injuries are a concern for a 178-pounder, but James can be a slippery return man/slash player if he stays healthy.

Jamal Morrow, Running Back, Washington State: A productive receiver out of the backfield who is pesky in the open field, Morrow is still on the mend from a broken foot he suffered in the Holiday Bowl. His versatility and toughness could make him a training camp standout.

Bilal Nichols, Defensive Tackle, Delaware: A former linebacker, Nichols is a weight room hero with NFL size and athleticism. He spent much of his Blue Hens career getting blocked by half the opponent's offensive line.

Foye Oluokun, Linebacker, Yale: A 229-pound linebacker-safety tweener, Oluokun enjoyed a stellar pro day after displaying range, thump and ball-hawk tendencies at the Ivy League level. He projects as a nickel defender who could emerge as a playmaker in the right system.

Malik Reaves and Trey Johnson, Cornerbacks, Villanova: Reeves is a big, tough bump-and-run corner. Johnson opened eyes with a reported 4.33-second 40 at his pro day. Both excelled at a high-FCS program with a track record of producing NFL prospects.