An assortment of top 2021 NFL Draft prospects opted out before they played a snap for their respective school this past season, and it's time to get reacquainted with them in the early stages of the pre-draft process.

From Penei Sewell to Walker Little, let's rank the best opt-outs who'll be a part of the 2021 class. 

19. Walker Little, OT, Stanford

The skinny: We haven't seen Little since Stanford's first game ... in 2019. He was a five-star recruit in the 2017 high school class and has immense size at 6-foot-7 and 310 pounds. Unsurprisingly, he's decently raw and needs to add weight/strength. 

18. Ambry Thomas, CB, Michigan

The skinny: Thomas is a speedy, man-coverage specialist who stands 6-0 and weighs somewhere in the 180s. He can get bodied by bigger receivers because of his size and doesn't have loads of experience entering the league. 

17. Sage Surratt, WR, Wake Forest

The skinny: Surratt is a heavy-footed rebounder with good twitch for his size and turns 50-50 balls into 80-20 balls down the field. He severely lacks speed but is a horse after the catch because of his thick frame. 

16. Tyler Shelvin, DT, LSU

The skinny: Shelvin's an unfathomably wide and stocky nose tackle who eats double teams for breakfast. He played around 370 pounds at LSU in 2019 -- which is a little concerning -- and actually can get up the field but does not have the sustained speed or handwork to be an effective pass rusher in the NFL. He'll instantly boost any teams' run defense, though. 

15. Jalen Twyman, DT, Pittsburgh

The skinny: When it comes to pass-rushing moves, Twyman is arguably the most impressive interior rusher in the class. He's flexible and plays with good agility to sneak through gaps to win the angle battle at the point of attack. His burst is lacking and he needs to get much stronger to deal with powerful guards at the next level. 

14. Jay Tufele, DT, USC 

The skinny: Master of the swim move, Tufele is difficult for guards to get their hands on during pass plays. He's a good athlete, too. His game is devoid of power and he's a liability in the run game. 

13. Kenny Gainwell, RB, Memphis

The skinny: Gainwell represents the future at the running back spot. He runs crisp, slot wideout routes and tracks it amazingly down the field. He's a little undersized for the running back spot in the NFL -- mostly due to his weight -- and isn't a true breakaway runner. His vision and cutting skills are impressive. 

12. Gregory Rousseau, EDGE, Miami

The skinny: I'm more down on Rousseau than the masses because he's very far from being a finished product. The vast majority of his production in 2019 was schemed or due to outstanding back-end coverage by Miami's secondary. A high rusher without much power or pass-rushing moves, the alluring part of Rousseau's profile is in his long, angular frame at 6-7 and 260 pounds.

11. Jamie Newman, QB, Georgia

The skinny: We never saw Newman in a Bulldogs uniform and for the first two months in 2019 at Wake Forest, he was one of the best quarterbacks in the country. Athletic with a well-built frame, Newman is dangerous as a runner, knows how to navigate the pocket, will fit the ball through tight windows and has awesome downfield touch. He just played in a gimmicky offense in college. 

10. Joe Tryon, EDGE, Washington 

The skinny: Tryon checks the physical box at 6-5 and around 265 pounds. And there's plenty of power to his game, against the run and when rushing the passer. He's an explosive, linear athlete and works well back to the inside as his main counter. Beyond a bull rush and a crossover, there aren't pass-rushing moves in his repertoire at this point.  

9. Nico Collins, WR, Michigan

The skinny: Collins is a contested-catch monster at 6-4 and 222 pounds. He's fast, too. Will he win as a separator in the NFL, though? 

8. Thomas Graham, CB, Oregon 

The skinny: Graham was an ultra-productive outside cornerback with the Ducks with the feet to hang in the slot. Not overly big nor fast, he routinely wins with twitch, instincts, and a natural ability to find the football as it's arriving.

7. Levi Onwuzurike, DL, Washington 

The skinny: Onwuzurike won from multiple alignments with the Huskies thanks to a sturdy lower half and long, powerful arms he uses very well. There's good bend and athleticism to his game as well. He's one of the most complete defensive tackles in the class. 

6. Jevon Holland, S, Oregon

The skinny: Holland was an elite playmaker during his two seasons with the Ducks, reeling in nine interceptions. Experience as a deep safety in 2018 and a slot defender in 2019, he's a legitimate multi-dimensional prospect. The concern about Holland's profile is whether or not he has the athletic gifts to be that type of game-changer in the NFL. 

5. Rashawn Slater, OT, Northwestern 

The skinny: Slater glides in pass protection and plays with phenomenal balance. He's ready for any pass-rushing move sent his way and his lower center of gravity allows him to anchor well against bull rushes. Is he long enough to thrive on the edge in the NFL? I think so. 

4. Caleb Farley, CB, Virginia Tech

The skinny: Farley is a high-caliber athlete on the perimeter with high-caliber mirroring ability and outstanding instincts in off coverage and zone.

3. Micah Parsons, LB, Penn State

The skinny: Parsons is an athletic freak with range and unusually deft abilities as a hand-in-the-dirt pass rusher for an off-ball linebacker. The only minor question arises with his lack of major production in coverage, but the skills are there for him to be a three-down player in the NFL and an effective one at that.

2. Ja'Marr Chase, WR, LSU 

The skinny: Chase was magnificent in 2019 as a redshirt sophomore during LSU's epic national title season. He bullied defenders in jump-ball situations, showcased deceptive speed down the field, and was dynamic after the catch. It's a challenge to find faults in his game. 

1. Penei Sewell, OT, Oregon

The skinny: Sewell has the athletic gifts like twitch and balance of a highly athletic center at 6-5 and 330 pounds. There's a touch of rawness to his game as a pass protector, but he mostly shuts down any rush attempt he sees. In space, for the run game, Sewell is jaw-dropping.