Not bad, kid. Bridgewater led the Vikings to an NFC North title and a playoff berth in only his second year as a starter. Along the way, he posted a respectable 88.7 passer rating. Offensive coordinator Norv Turner and head coach Mike Zimmer wouldn't mind if Bridgewater took more shots down the field, but that might come in time. Why not Derek Carr here? The Raiders' signal caller is a year and a half older than Bridgewater, who doesn't turn 25 until November 2017.

Bell is quite simply the best running back in pro football, whether he's under 25 or not -- in fact, Bell doesn't turn 25 until February 2017, which is extraordinary, considering what a polished player he already is. The production aside, the fact that he hasn't lost a fumble since 2013 points to what a complete player he is at such a young age. The issue now? Staying healthy.

Considering he only started 12 games, it's remarkable what Gurley was able to accomplish in his rookie season. The Offensive Rookie of the Year racked up 1,106 rushing yards, third-most in the NFL, while also posting a sterling 4.8 yards per carry. He's like the love child of Eddie George and Eric Dickerson.

What Hopkins was able to do with Brian Hoyer, Ryan Mallett and T.J. Yates last season -- racking up 1,521 receiving yards (third-most in the NFL) and 11 receiving touchdowns on 111 catches -- was beyond exceptional. Hopkins barely beats out Allen Robinson here, as the Jaguars' receiver has the benefit of playing with quarterback Blake Bortles, who is better than anyone Hopkins has had in his first three seasons. (We'll see about Brock Osweiler.) Oh, but it's close. (I really tried to sell Robinson and got yelled at in the NFL Now newsroom. Researcher Mark Dulgerian looked up from Tinder long enough to say no on Robinson ... so I guess he swiped left.)

If we didn't place Beckham on this list, our website would probably crash, and we would have to relaunch as NFL.org or NFL.edu. Beckham has enjoyed sensational moments, along with a few lows, on the way to stardom. That said, his rookie campaign was one of the premier freshman seasons in NFL history -- he averaged a staggering 108.8 yards and one touchdown per game. For his career, he's posting 102 yards every time he goes out there.

After struggling to work himself into the offense as a rookie in 2014, Ebron improved in 2015, catching 47 of 70 targets for 537 yards in what was a tough season overall in Detroit. That said, with Calvin Johnson's retirement, coach Jim Caldwell will have to lean on his young tight end. Ebron just turned 23 in April.

Havenstein protected Rams quarterbacks well enough that they could deliver the ball last season (not that they delivered it accurately or anything). Though he's not a beast in the run game, Havenstein is a young developing player who started 13 games on Jeff Fisher's offense, helping Todd Gurley thrive as a rookie.

Bakhtiari was far from perfect in 2015, and he wasn't perfectly healthy, either. Yet, the young tackle held down the fort in pass protection, allowing a mere three sacks. Per the analytics mavens at Pro Football Focus, Bakhtiari struggled to be consistent in the run game. But that was a team epidemic, especially considering running back Eddie Lacy's issues. Bakhtiari is one of the oldest players on our list, as he'll turn 25 on Sept. 30. #oldage

The hidden secret to the Panthers' success in 2015 was the improved play of the offensive line, including Norwell. The left guard allowed all of two sacks in 2015. Of course, a guard's main focus is to pound in the run game, and the 24-year-old succeeded in that area, as well -- Carolina's ground attack (and the play of back Jonathan Stewart) greatly contributed to the team's Super Bowl run.

Joel Bitonio dominated the Mountain West in college, per Mr. Dulgerian, but that was as a left tackle. In Cleveland, he was moved to guard, where he was fantastic as a rookie in 2014. Bitonio might not have been better in Year 2, starting with the fact he played only 10 games. But there were many ills with that Browns' offense, and the line was the least of the club's worries. My guess is that with Hue Jackson -- the running back whisperer -- in charge, Bitonio will make hay in the ground game. He turns 25 on October 11. (Ron Schwane/Associated Press)

The rookie from Missouri performed rather well in 2015, replacing the departed Rodney Hudson and starting 15 games. Morse is a bit tall to be playing center, as he hovers between 6-foot-5 and 6-6, but that's OK. He was called for one penalty all season while being a viable run blocker. And hey, he was thrust into the starting lineup and made a position change from tackle. Not bad for a second-round pick.

The craziest thing about Williams being on this list is that when last season started, he had just turned 21! The Jets' defensive end will be all of 22 this summer as he looks to improve upon his sterling rookie year. Williams was in on 62 tackles and three sacks while starting 15 games for Todd Bowles in 2015.

Lawrence's name isn't as familiar as some of the others on this list, but you should get to know him. The second-year pro from Boise State posted 55 tackles and eight sacks for the Cowboys last season. Oh, and after coming back from injury as a rookie, Lawrence racked up two sacks in the 2014 postseason. The downside: He's facing a four-game suspension to start the 2016 campaign.

The Steelers' defense sure fared better than most fans -- yes, even Steelers fans -- expected last season. Tuitt was a big reason (literally) why ... the 6-6, 303-pound lineman cranked out 6.5 sacks and a whole bunch of hurries in a defense that relies on its OLBs for pocket pressure. Tuitt is certainly a building block in Pittsburgh.

The Bears needed a solid draft in 2015, and they can certainly point to their second-round pick as a success. Goldman might not have played every down, but he was able to apply pressure in part-time duty. Besides collecting 4.5 sacks (not bad for a rookie DT), he made plays in the run game, proving to be part of the young nucleus coach John Fox needs to retool Chicago's defense.

Barr was simply outstanding for a second-year pro. Despite fighting injuries and missing two full games, the Vikings' outside linebacker compiled 68 tackles, 3.5 sacks, one interception and seven passes defensed. The sack total might not wow you, but generally 4-3 OLBs are asked to cover as much as they're asked to rush the passer. Barr also forced three fumbles last season. Not bad.

The rundown on Smith coming out of Mississippi State was that he had everything you wanted from your Y2K-era 3-4 OLB edge rusher (a lot of acronyms there). Per my conversation with NFL Now researcher and draftnik @MarkDulgerianOS, Smith had the measurables, which is why he went so high in the second round. Last season, he posted eight sacks and forced three fumbles -- and he only has room to grow. Note: Mark D wanted Aaron Lynch here.

Mosley might not have followed up his sterling rookie campaign with the All-Pro leap forward people were expecting in 2015, but he is still one of the top young players in the NFL. The Baltimore ILB compiled over 100 tackles while being adequate in coverage. Look for him -- and the entire Ravens team -- to be healthier this coming season ... and much better.

We're accounting for both 4-3 and 3-4 defenses here -- thus, there is room for Hicks, who was in the running for Defensive Rookie of the Year until getting hurt midseason. Despite playing only half the season, Hicks produced two interceptions and three fumble recoveries, and he even managed to score a touchdown.

Peters led the NFL in interception-return yards by a wide margin (his 280 were followed by Trumaine Johnson's 136) and tied for the lead in picks (eight) and pick-sixes (two). Kansas City desperately needed help in the secondary coming into the season, and Peters solidified the left corner spot for a Chiefs team that made the playoffs after starting 1-5. The Defensive Rookie of the Year is one of the most exciting players to come into the league at corner in a long time.

The 2015 campaign was a down year for the Bills' defense, but not because of Darby. Marcus Peters deservedly took home the DROY hardware, but when you dive into the numbers, Darby is right there. He allowed fewer receptions, yards and touchdowns than Peters, while posting more tackles. What a second-round find.

Some league observers had Mathieu as their Defensive Player of the Year before he went down in that Sunday night game in Philly. The "Honey Badger" is the new Charles Woodson -- that rare player who can do so many things well. Cardinals defensive coordinator James Bettcher can move him around like the queen on the chessboard.

Clinton-Dix has quietly emerged as one of the rising defensive backs in the NFL; before too long, he could become an elite player at the safety position. Clinton-Dix was very good in coverage, giving up only one touchdown reception. He also amassed 83 solo tackles, a very high number for a safetyman. And to think, he's only 23 years old.

Santos enjoyed a productive 2015 season, making good on 30 of 37 field-goal attempts and scoring 129 points, sixth-most in the league. Over half of Santos' misses were from 50 yards or more. In 2014, he converted 25 of 30 kicks. He might not be the best kicker in the league, as he has missed a couple of short kicks the last two years, but overall, he has performed consistently and has many years in the NFL ahead of him.

Darr makes this team partially because he had no competition (OK, save for Bradley Pinion in San Francisco). That said, Darr's gross average of 47.6 put him in the top five in the league, while his 30 boots inside the 20 ranked eighth overall.