Odell Beckham Jr. did not need much time to make his mark on the NFL. Neither did Aaron Donald, Mike Evans and a handful of other players drafted in 2014.

However, the vast majority of NFL prospects require more seasoning before making a significant impact. The reasons are numerous. Most players enter the league between 21-23 years of age and need more time for their bodies to mature. NFL playbooks are generally denser and more complex than those used in college. Even the length of the season can prove daunting -- players will play 13 games at most during a college season as opposed to 20 (four preseason, 16 regular season) in the pros.

So while a large portion of fans focus on the incoming rookie class, perhaps the more intriguing storylines will come from those about to break out during their second season in the NFL.

The Minnesota Vikings took an aggressive approach in last year's draft, trading back into the first round in order to acquire Louisville signal caller Teddy Bridgewater. After spending an early stretch of the season learning behind journeyman Matt Cassel, Bridgewater took the reins of the offense and gradually adjusted to the speed of the NFL. The results weren't always optimal, but by the end of the season, Bridgewater had distinguished himself as the best quarterback in his draft class.

The key for Bridgewater is improving upon his first year. Still only 22, he needs time to grow into his body. However, his understanding of the offense has already exceeded expectations, and with his first full offseason to work exclusively with the Vikings, Bridgewater could establish himself as a legitimate threat at quarterback in 2015.

Safeties entering the NFL endure a steep curve. Not only are the receivers on average bigger, faster and craftier than those at the collegiate level, but quarterbacks are also adept at baiting defensive backs by looking one way before throwing the ball to a different spot. The Green Bay Packers' Ha Ha Clinton-Dix went through this process in 2014, and has entrenched himself as the starting free safety in Dom Capers' defense.

The next step is learning to avoid costly mistakes. Though Clinton-Dix's instincts generally led him to where he needed to be, poor tackling allowed too many plays to be extended. If he can reduce the number of missed tackles, Clinton-Dix has already shown the range and ball skills of a Pro Bowl safety.

Brandin Cooks

While Sammy Watkins, Evans and Beckham Jr. garnered the most attention of the first-year receivers last year, many draft analysts believed it was Brandin Cooks who would have the most success as a rookie. Cooks not only possesses elite-level athleticism and explosiveness, but he was fortunate to land in New Orleans with Sean Payton, one of the league's most visionary offensive play callers. However, injuries and the general decline of the New Orleans Saints kept Cooks from producing big numbers in 2014.

That should change this year. Cooks enters camp as a starting receiver in an offense that will target him often. If he remains healthy, the Oregon State product will serve in as a deep threat, slot receiver and perhaps a running back à la Randall Cobb.

Kyle Fuller

At one point during his first season with the Chicago Bears, Kyle Fuller appeared to be on track for Defensive Rookie of the Year honors. The former Virginia Tech cornerback produced an astounding five takeaways during his first three games. Ultimately, Fuller was unable to keep pace with a deep class of defensive rookies, becoming an afterthought in the award discussion as the season progressed.

Though injuries and the rookie wall kept the young corner from breaking out a year ago, a healthy, more seasoned Fuller could make a big impact in 2015. Not only should his experience help him overcome some weaknesses, but the presence of new defensive coordinator Vic Fangio could have a very positive influence on Fuller's development.

Unlike most years, 2014 NFL Draft didn't have a quarterback debate sucking up all the oxygen in the room. Instead, pundits argued whether Auburn's Greg Robinson or Texas A&M's Jake Matthews deserved to be the first offensive tackle to come off the board.

While Robinson ultimately earned that distinction, it is Matthews who might have the brighter future. The Atlanta Falcons took him with the sixth overall pick and immediately threw him into the starting lineup. Though he struggled, Matthews is poised to take a huge leap in his second year.

Ryan Shazier

When the Pittsburgh Steelers invested the 15th overall pick in Ryan Shazier, the hope was that the Ohio State product could eventually become the rangiest off-ball linebacker in the NFL. Injuries and inexperience prevented Shazier from playing up to that potential as a rookie, but that should begin to change this year.

In terms of speed and quickness, very few linebackers can compare with Shazier. His only major physical deficiency is his size (he played his college ball between 210 and 220 pounds), but with a full offseason under his belt, he should be able to add sustainable weight. Unless injuries intervene, the Steelers expect a big year out of Shazier.

Overlooked due to his 5'9 stature, Jason Verrett joined the San Diego Chargers and immediately became a key member of their secondary. A labrum tear shortened his season, but while healthy Verrett was San Diego's top cover corner. His instincts made the TCU product a natural fit in John Pagano's scheme.

Now, Verrett just needs to improve his ball skills. While he held quarterbacks to a 76.2 passer rating on balls thrown in his direction, per Pro Football Focus, he forced just one turnover. If he can more consistently get his hands on the ball, the Chargers will have a long-term solution at one of their cornerback spots.