When the NFL's brightest stars hit the open market, the money goes sky-high. Now that Baltimore Ravens quarterback Joe Flacco has been signed to the richest contract in NFL history, and the Denver Broncos have designated left tackle Ryan Clady their franchise player, the next best free-agent-to-be, Cliff Avril, is set up for a huge payday.

Wait, who?

That's right: CBS Sports has the Detroit Lions defensive end ranked as their No. 3 overall free agent, behind only Flacco and Clady. Big-name pass-rushers like Osi Umenyiora and Dwight Freeney lag far behind Avril.

Avril was rated the No. 8 available free agent in this column, but no matter who's doing the grading, it's clear: Avril is a big-time free agent, even if he doesn't have big-time buzz.

But is he a big-time player?

A Tantalizing Prospect

Avril would be a prototypical "'tweener," if such a thing were possible. Standing at 6'3", his current 260-pound weight is up from the 253 pounds he weighed at the NFL Scouting Combine, and way up from the 225 pounds he was listed at as a college recruit.

At Clay High School in Green Cove Springs, Florida, Avril played defensive end. Despite the deep talent pool in Florida, Avril's 80 tackles—including 11 TFL and nine sacks—earned him second-team all-state.

At the D-I level, though, his athleticism seemed to make him a natural outside linebacker. Rivals.com named Avril the No. 37 outside linebacker in the country; he committed to Purdue as a stand-up defender.

Throughout his four-year college career, though, Avril bounced back and forth between outside linebacker and left defensive end. Per NFL.com, Avril started 12 of his 49 career games played at strong-side linebacker and had 24 starts at left defensive end.

Between both positions, College Football Reference says Avril racked up 157 total tackles, 32.5 tackles for loss and 12.5 sacks. Avril then backed that up with ridiculous combine numbers.

Per NFL Combine Results, Avril worked out with the linebackers. He cut a 4.51 40-yard dash, 32.5" vertical leap, 117-inch broad jump and 6.90 three-cone drill. Had he been running with the defensive ends, those numbers would have ranked first, third, third and first respectively.

A Bad Fit?

Avril thought his athleticism, versatility and production would land him in the second round of the draft. Avril told the Detroit Free Press his memories of his draft day were "horrible," then walked that back a bit:

"I mean, it wasn't horrible. I don't want to say horrible, but initially I wasn't too pleased with it."

The Detroit Lions, however, couldn't have been more pleased with their third-round pick.

It was an odd fit of prospect to team. Avril seemed like a natural 3-4 outside linebacker. At the time, though, the Lions were running a Tampa 2 defense under Rod Marinelli. Physically, Avril was closer to legendary Buccaneer strong-side linebacker Derrick Brooks than rush end Simeon Rice.

Nevertheless, Marinelli installed Avril as a defensive end, and the move didn't take long to pay off. In 15 appearances and four starts, Avril was second on the team in sacks with five, led the team in quarterback hits with seven and finished fifth on the team in quarterback hurries with nine.

Another Position Change and a Revelation

The question of Avril's fit in the Tampa 2 became moot after his rookie season; the Lions ditched Marinelli and his scheme after the Lions finished 0-16 that year.

That question was quickly replaced with another. Jim Schwartz and Gunther Cunningham installed the so-called wide nine scheme; one which calls for bigger, stronger defensive ends who can play the run as well as rush the passer.

With a heavier, more balanced workload in 2009, Avril led the team in sacks (six) and quarterback hits (five). He tied for second on the team with hurries (16). Unfortunately, Avril was also the most-penalized Lions defensive lineman that season; PFF counted seven flags thrown his way.

In 2010, it all finally clicked for Avril. His nine sacks were second only to rookie Ndamukong Suh (11), and his 44 hurries led the team by a mile (Suh was second with 24). Avril was PFF's 11th-best 4-3 defensive end that season and had the sixth-best pass-rush grade (plus-23.9).

In 2011, Avril started all 16 games for the first time. He lead the team in sacks for the second time, with 11. Avril also lead the team in quarterback hits, with nine, and quarterback hurries, with 41.

Even more importantly, Avril forced an incredible six fumbles—second-best in the NFL—and recovered three of them. One of those sack/fumble recoveries finished with a touchdown return, and it came against a player you may have heard of:

In that clip, you see everything that makes Avril dangerous: a quick first step, great speed around the corner, a good outside move and a lethal tomahawk chop.

Revelation an Illusion?

Avril's 2011 seemed "better" than his 2010; he notched more sacks, more quarterback hits and revealed a game-changing knack for forcing turnovers. Avril's pass rush, though, was actually less consistent; his quarterback hurries fell from 44 to 38, and his PFF pass-rush grade plummeted from from plus-23.9 to plus-5.9.

Nevertheless, Avril was a huge part of the Lions defense, and his playmaking skills were a big reason the Lions went from 0-16 to the playoffs in just the span of his four-year rookie contract.

That contract, though, was up.

The Lions wanted Avril back; Avril wanted to earn his market value. Given the monster six-year deal fellow free-agent defensive end Mario Williams signed, loaded with $50 million in guarantees, the Lions' reported final offer of a three-year contract worth $30 million ($20 million guaranteed) wasn't enough for Avril.

Instead, Avril played under the franchise tag, earning $10.6 million for one year's work.

Did the Lions get their money's worth? That's an open question.

Avril had 10 sacks, five quarterback hits and 20 hurries in 2012. That's good production, but fewer than half as many hurries as he'd record in either 2011 or 2010. Avril's PFF pass-rush grade fell to minus-0.4, by far the lowest of his career. His turnover knack also left him; Avril only forced two fumbles in 2012.

Use Your Illusion

Just like last spring, Avril and the Lions likely have different ideas of Avril's worth. Avril recently told Sirius XM Radio (via Mlive.com) he's using the contracts of the Carolina Panthers' Charles Johnson and Arizona Cardinals' Calais Campbell as benchmarks; he even half-jokingly brought up the Williams contract:

I would love to get Mario's deal. Who wouldn't? Those are some great numbers. My thing is I want to keep getting better. I'm still young. I'm only 26 years old. The sky is the limit as far as that. Those are some great numbers, hopefully we can get somewhere near there.

Avril hit the nail on the head: He turns 27 this year.

Former BYU defensive end—and current hot draft prospect—Ziggy Ansah, whom some peg as a possible replacement for Avril with the Lions' No. 5 overall pick, will turn 24 this year. While Ansah has only played two seasons of football in his life, Avril is a five-year NFL veteran with 42 career sacks.

Draft prospect Dion Jordan, whom many consider a possibility (if not probability) to go to the Philadelphia Eagles at the No. 4 slot, is three inches taller than Avril, weighs five pounds less than Avril did at the combine and 12 pounds less than Avril does now.

Yet, Jordan's amazing combine workout numbers are, at best, no better than Avril's were.

This untapped potential is what has Avril near the top of free-agent ranking lists. Yes, untapped: despite five seasons in the NFL, Avril's never been used in a way that maximizes his skills.

A Bad Fit

For almost all of Avril's career with the Lions, he's been a left defensive end. Rather than playing the wide nine-technique spot against lean, athletic left tackles, Avril's gone up against massive right tackles. Avril either has to beat them cleanly with speed and outside moves (as above, in the Tim Tebow clip) or not at all.

Against slimmer left tackles, Avril should be able to mix in useful power rushes and inside moves, making him much less one-dimensional as a player and his speed rush that much more effective.

Better yet, a team could unmake the mistake Marinelli and the Lions arguably made back in 2008 and sign Avril to play 3-4 linebacker. Instead of trying to be Kyle Vanden Bosch but 20 pounds too skinny, Avril could be LaMarr Woodley with 4.51 speed instead of 4.62 speed.

After five seasons in the NFL, Avril has proven he can rush the passer at an elite level. Yet, at 26, most of his potential still hasn't been realized. If there's anything that the draft and free agency prove year after year, it's that NFL teams always pay for youth and upside.

Avril may not get Mario Williams money, and NFL fans may not be talking about him as an elite free agent. There's no doubt, though, that the people who sign NFL team checks are practicing their zeroes and commas while daydreaming about what Avril can do for their team.

All statistics per Pro Football Focus except where noted; subscription required.