5 NFL Undrafted Free Agents Who Must Impress at OTAs

Despite going 50-3 at Boise State, Kellen Moore went undrafted and will battle for the backup quarterback position in Detroit.

He's one of the few well-known college players that standout among those who didn't hear their name called during the draft, so it's apparent that Moore has a lot to prove during OTAs.

Before we address college football's all-time winningest quarterback though, let's see other notable undrafted free agents that must impress before training camp.

Full view of undrafted free agents.

Vontaze Burfict: LB, Bengals

Vontaze Burfict went from a potential day one selection to an undrafted free agent so fast that is was mesmerizing to watch.

After a solid first two years at Arizona State, the linebacker flopped as a junior in 2011 and the offseason was a downward spiral to forget. So by the time the 2012 draft started and finished, it was not surprising to see Burfict still available.

In Cincinnati, Burfict has to develop quickly also because the Bengals are a team on the rise with a top five potential defense. Burfict still needs to develop his reads and awareness against the pass, display better control when changing directions and reacting quicker to the run.

Now take into account the Bengals' division and Burfict's toughness will be challenged this summer. The AFC North presents improved ground games to set up play-action, so recognizing the developing plays will be crucial.

Burfict undoubtedly has the speed and power to make plays and deliver hits, but his mental approach to prepare for the NFL's faster game and more complex schemes must impress before the preseason.

Jeff Fuller: WR, Dolphins

Possessing mid-round talent, Texas A&M's Jeff Fuller had to wait until after the draft to find a team.

The good news is that he's reunited with quarterback Ryan Tannehill as the Dolphins selected him at No. 8 overall. In addition, Fuller has the luxury of playing for Mike Sherman again as he was the Aggies head coach.

Still, all that doesn't guarantee Fuller will find a final roster spot in South Florida. Miami has decent receivers in place with Brian Hartline and Davone Bess, but does need a true No. 1 target to help balance the offense.

Fuller has that potential as he caught 142 passes the past two seasons, but 2011 was a disappointing campaign. With the ability to stretch a defense, Fuller has to improve at being more physical and getting open underneath.

His size does provide an advantage near the red zone, but Fuller has to set up a safety from always playing over the top by being productive at the second level. This also helps develop a better ground game off play-action so Miami's offense can remain multidimensional.

Lacking the dominant explosiveness at the snap however, Fuller must get stronger to separate early from the more physical defenders. If not, he'll be fortunate to contribute on special teams as other receivers like B.J. Cunningham and Rishard Matthews are also battling for a contributing role.

Lance Dunbar: RB, Cowboys

Lance Dunbar comes into Dallas undersized and largely unknown despite his college numbers.

While at North Texas Dunbar compiled over 4,000 rushing yards and almost 1,000 receiving yards from 2009-2011. He also scored 47 touchdowns during that span and averaged 5.5 yards per carry.

Now, obviously this was mainly against the Sun Belt Conference which doesn't compare to any BCS competition. Nonetheless, the consistency and dominance proved Dunbar at least deserved a look and Dallas has provided that opportunity.

Presenting good top speed, acceleration and explosion, Dunbar has to transition that skill set to special teams. The Cowboys already have two young backs in DeMarco Murray and Felix Jones, so the odds of him getting any carries in 2012 is slim-to-none.

That said, Dunbar can make an impression on punts, kickoffs and kickoff returns. His vision as a running back bodes well as a kick returner and to make tackles on punts and kickoffs. As long as Dunbar proves his value in this area then that only increases his chances of seeing time in the backfield.

After a ridiculous college career and being the big man on campus, Dunbar must prove his talent to himself and skeptics once again.

Case Keenum: QB, Texans

Houston Cougar's quarterback Case Keenum threw for over 5,000 yards thrice times during his career and twice over 5,600.

2011 was his best year in the biz with 48 touchdowns to only five picks and a 71.0 completion percentage and Houston finished 13-1 (ranked No. 14).

But, Keenum's numbers weren't impressive enough to get selected as the competition was low and he hardly ever took a snap from under center. Now, the man does have a stronger arm and more mobility than Kellen Moore, so he's arguably a more NFL-ready quarterback.

The Houston Texans are a great place to test Keenum's ability as well, because of other quarterbacks Matt Schaub and T.J. Yates. Schaub has durability concerns after 2011 and Yates has to prove he can continue to get the job done when called upon.

As for Keenum, the Texans do provide Andre Johnson and Owen Daniels in the passing game and Arian Foster in the backfield. So the tools are set up for success, but Keenum still needs to make quicker reads, look off safeties, be more accurate downfield and have more poise in the pocket.

When pressured the happy-feet kicks in full force (namely the Conference USA title game) and reading pre-snap must improve. The mechanics are in place for success, but the NFL will significantly challenge Keenum's cerebral approach to developing as a quarterback.

Kellen Moore: QB, Lions

We could reasonably say that Kellen Moore not getting drafted is a travesty for college football. After all, winning 50 games regardless is unbelievable and the man improved through each season at the helm.

What's more impressive is that Moore had his best season as a senior in 2011, but did so without his two favorite targets (Austin Pettis, Titus Young) as both were rookies in the NFL. Moore's final two seasons were 71.3 and 74.3 completion percentages and he also averaged 9.35 yards per pass attempt during that span.

The downside is Moore's arm strength, mobility and lack of experience under center. Boise State rarely took him out of shotgun and he didn't need to make many throws downfield.

All of this needs to get proven during OTAs because Moore does possess the cognitive approach and ability to read defenses pre-snap rather well. Those will help the transition under center, but it's his footwork and setup to making all the throws that is vital to competing for the backup spot.

Include the increased level of competition and Moore will feel the pressure quite often. What he does before the snap is more important, because the lack of mobility allows a defense to not blitz as often.

If Moore can favorably position himself and the receivers by making audibles and adjustments on the fly, that's his best chance to dice up defenses before the preseason.

John Rozum on Twitter.