If you're a fan of the NFL draft, it's never too early to speculate about future No. 1 picks and first-rounders.
While college players aren't allowed to enter the draft until after their third year out of high school, there are some prospects to watch for the 2021-23 classes, from underclassmen to high school recruits. It's still early to speculate on how their careers will pan out, but they already have given a glimpse of what they could become once they reach their full potential.
After we ran through the quarterbacks to know in the 2020 class, here are five potential prospects to watch in the three classes after that:
Jump to a draft class:
2021 | 2022 | 2023
2021 NFL draft

Trevor Lawrence, QB, Clemson
Lawrence, the No. 2 overall prospect in the 2018 class, battled his way to the starting spot, beating out incumbent Kelly Bryant at Clemson. He led Clemson to an undefeated regular season, a berth in the College Football Playoff and, eventually, a national championship win over Alabama. Lawrence threw 30 touchdown passes to only four interceptions and inspired conversations on whether he could make it in the NFL after only one season in college.
Trevor Lawrence made a big impression on every field he ever played on, from Knoxville, Tenn., to Cartersville, Ga., but we didn't pay attention until he made his point on the big stage in Santa Clara.

Rondale Moore, WR, Purdue
Moore doesn't have prototypical size, but with smaller, diminutive players having seen success in the NFL in recent years, there is a definite lane for Moore to succeed. He's listed at 5-foot-9, 180 pounds but ran a 4.33-second 40-yard dash in high school and is a home run threat every time he touches the ball. He is a Swiss Army knife, accounting for 213 yards and two touchdowns rushing, 1,258 yards and 12 touchdowns receiving and 662 yards returning kicks last season. An NFL team could put him all over on the field -- as a receiver and in the return game -- and let him loose.

Penei Sewell, OT, Oregon
It is difficult for an offensive lineman to make this list because the transition from high school to college usually takes time. Sewell, however, started at left tackle for Oregon before suffering an injury midway through his freshman season. At 6-foot-6, 345 pounds, he has good size, and if he continues on an upward trajectory, NFL teams could be clamoring to add him to their roster.

Justyn Ross, WR, Clemson
The 6-foot-4, 205-pound Ross has most of what NFL coaches are looking for in a receiver, with size, hands and the ability to make big plays when called upon. He made a huge impact on Clemson's offense in his first season, catching 46 passes for 1,000 yards and nine touchdowns -- including 12 receptions, 301 yards and three touchdowns in two College Football Playoff games. If he continues on this path, Ross will hear his name called very early in the NFL draft when he decides to enter.

Micah Parsons, OLB, Penn State
Parsons has the athleticism to play linebacker, defensive end and even running back, which is a rare trait for a prospect listed at 6-foot-3, 245 pounds. He was a five-star recruit out of high school and already showed a ton of upside in his first season at Penn State. At linebacker, Parsons had 83 total tackles (which led the team), 1.5 sacks and two forced fumbles while playing in 13 games. He has everything an NFL defense would want, with size, athleticism and versatility. If his career continues the way it started, he will be a coveted prospect.
2022 NFL draft

Nolan Smith, DE, Georgia
Smith was the No. 2-ranked prospect in the 2019 class. At 6-foot-3, 235 pounds, Smith can do a little bit of everything on defense, whether it's lining up at defensive end or at linebacker. He is an outside linebacker in Georgia's defense, which means he'll get the chance to rush off the edge and display his athleticism. If Smith has the kind of success most scouts think he can have, he likely will find himself sitting in the green room at a future NFL draft.

Kayvon Thibodeaux, DE, Oregon
Thibodeaux is one of a number of California prospects who headed north to play for Oregon. As the No. 1-ranked recruit in the 2019 class, he was an important addition to the Ducks' class and for future recruiting as well. Listed at 6-foot-5, 240 pounds, he can be the type of edge rusher any NFL team would like to add to its roster. He has some refining to do, but based on his size, potential and current ability, the expectations are high for Thibodeaux's future.

Derek Stingley Jr., DB, LSU
The ideal NFL cornerback is now tall, long, can cover and also able to help in the running game. Stingley checks off all of those boxes and already has started to turn heads at LSU. The 6-foot-1, 195-pound corner enrolled early and was able to participate in bowl practices. The buzz about those practices was that Stingley was everything the coaching staff hoped he would be. The top-ranked corner in the 2019 class has a chance to start early on for LSU and could continue its tradition of elite defensive backs.

Evan Neal, OT, Alabama
Every team in the NFL would love to have a 6-foot-7, 360-pound offensive tackle who can move on their roster. Neal was part of a large group of top-ranked tackles who could have made it on this list, including Texas A&M signee Kenyon Green, Tennessee signees Darnell Wright and Wanya Morris and fellow Alabama signee Pierce Quick. Neal has all of the tools to become another top draft pick along the line for the Crimson Tide. If past success is any indication, the odds that he will pan out are in his favor.

Zach Harrison, DE, Ohio State
If Ohio State's track record at defensive end says anything, Harrison should be a top pick once he is eligible. He has a ton of upside and potential, but it has yet to be realized because he hasn't played a down of college football. He entered college at 6-foot-6, 245 pounds and already has put on 10 pounds since arriving, according to his listed weight. He has the size, potential and ability that every NFL team is looking for on the edge.
2023 NFL draft
Zachary Evans, RB
Undecided
Evans is the No. 1-ranked player in the country. It doesn't matter where he ends up, though, as his talent, size and potential are enough to get him on this list. He and Leonard Fournette are the only two running backs to hold the top spot in the ESPN 300, which says a lot about Evans. The phrases "can't-miss" and "no-brainer" have been used by evaluators when talking about Evans and his future.
Justin Flowe, LB
Undecided
Flowe is an aggressive, confident linebacker who isn't afraid of anybody. He went to camps as an underclassman and made sure the older prospects knew who he was with his play and his mouth. He's the No. 7-ranked recruit overall, the top linebacker and the highest-ranked prospect from California in the class. At 6-foot-2, 225 pounds, he has the size to transition to college and eventually to the NFL. No matter what defensive scheme he plays in, he's going to bring confidence and a hard-hitting mentality with him.

Julian Fleming, WR
Committed to: Ohio State
The Buckeyes are adding a few talented receivers in this class, and Fleming has the potential to be a highly productive player in their offense. At 6-foot-2, 200 pounds, he's the top receiver in the class and has shown his skills against some of the nation's best prospects on numerous occasions. He has most of what evaluators are looking for in a receiver, and his skill set should translate well to the NFL when the time comes.

Myles Murphy, DE
Committed to: Clemson
The Tigers saw their entire starting defensive line chosen in the most recent NFL draft, and with the way their coaching staff is recruiting, there's a chance we see quite a few more Clemson names called in the future. Murphy could be one of them. A 6-foot-5, 271-pound defensive end, Murphy could be special in that defensive front. He is one of a few defensive linemen committed to the Tigers in this class who could've made this list, along with defensive tackle Bryan Bresee, but Murphy fits well with what every NFL team wants in a defensive end in regards to size and athleticism.
Darnell Washington, TE
Undecided
NFL teams are always looking for big, strong tight ends who can be versatile in helping with the passing game and blocking. Washington is a 6-foot-8, 250-pound tight end with good speed for his size. Having a pass-catcher with that size to create mismatches in coverage is something NFL teams like to have. Considering that two tight ends were selected in the first round of the 2019 NFL draft, if Washington can have a productive college career at whichever school he chooses, he could be a highly coveted NFL prospect.