Eight of the first 19 players chosen in the 2019 NFL draft were defensive linemen, but college football is still overflowing with quality pass-rushers and run-stoppers. From Alabama's Raekwon Davis to Michigan State's Raequan Williams, quarterbacks won't be able to rest easy this fall.

Which teams project to have the best defensive lines in 2019? Returning production and year-over-year success in regard to sacks and run defense were the primary criteria for this ranking.

For instance, Michigan State was an obvious candidate for the top spot because it gets back all of last year's key linemen. The Spartans have also boasted one of the nation's best run defenses in four of the past six seasons.

Strength of schedule (or lack thereof) was also a minor point of consideration. For the most part, it was irrelevant. However, lack of difficulty was enough to warrant a top-10 spot for Tulane, and absurd difficulty kept Auburn out of the top five.

One final note before we dive in: Ohio State's Chase Young may well be the No. 1 overall pick in the 2020 draft, but the Buckeyes were so woefully incapable of stopping the run last season that they cannot reasonably have a projected top-10 unit.

10. Tulane Green Wave

Key players: Patrick Johnson (49 tackles, 16.0 tackles for loss, 10.5 sacks, 4 forced fumbles), Cameron Sample (40 tackles, 4.0 sacks), De'Andre Williams (38 tackles, 2.0 sacks), Jeffery Johnson (30 tackles), Davon Wright (18 tackles, 2.5 sacks), Carlos Hatcher (15 tackles, 2.0 sacks), Juan Monjarres (2.5 sacks)

The star

Patrick Johnson had 10.5 sacks last season, tied for ninth-most nationwide. Everyone in the top eight either graduated or left a year early for the NFL, so no active college football player had more sacks in 2018 than Johnson. It was quite the sophomore-season explosion for a defensive end who averaged only one tackle per game in 2017. And he finished strong, recording at least a half-sack in nine of his final 10 games.

Synopsis

Tulane is the only Group of Five program in our top 10. That's because of its sheer volume of returning production. The Green Wave ranked eighth in the nation with 3.15 sacks per game last season. With the exception of Robert Kennedy (32 tackles, 3.0 sacks), all of the defensive linemen from that pass-rushing unit are back.

As far as NFL potential is concerned, there are a few dozen teams with better defensive lines than Tulane. Factor in the strength of schedule and projected statistics, though, and the Green Wave ought to put up impressive numbers in 2019.

9. Iowa Hawkeyes

Key players: A.J. Epenesa (37 tackles, 10.5 sacks, 4 forced fumbles), Chauncey Golston (35 tackles, 3.5 sacks), Cedrick Lattimore (21 tackles, 1.0 sacks), Brady Reiff (12 tackles, 1.0 sacks)

The star

A.J. Epenesa—a 5-star recruit in the class of 2017—was one of the highest-touted players ever to sign with Iowa, and he has been every bit as good as advertised. Along with Tulane's Patrick Johnson, Epenesa has the most sacks among returning players nationwide. B/R's Matt Miller has Epenesa projected for the No. 3 overall pick in the 2020 NFL draft.

Synopsis

Iowa's front seven did a terrific job last year, ranking 10th in yards allowed per carry and recording 35 sacks. But the Hawkeyes lost Parker Hesse and Anthony Nelson, two defensive linemen who had been team leaders for each of the past three seasons.

Epenesa may single-handedly prove us wrong, but Iowa doesn't have a rich enough history of pass-rushing dominance to be ranked any higher than this. Frankly, it's a testament to Epenesa's talent that we're even willing to consider a team that neither recruits at an elite level nor has more than two returning players with multiple sacks in 2018.

8. Auburn Tigers

Key players: Derrick Brown (48 tackles, 4.5 sacks), Marlon Davidson (46 tackles, 3.5 sacks), Nick Coe (27 tackles, 7.0 sacks), Big Kat Bryant (18 tackles, 3.5 sacks), T.D. Moultry (11 tackles, 1.5 sacks), Richard Jibunor (8 tackles, 2.0 sacks), Tyrone Truesdell (9 tackles), Daquan Newkirk (7 tackles), Coynis Miller Jr. (5 tackles)

The star

Had Derrick Brown declared for the 2019 draft, he would've been a borderline first-round pick. (B/R's Matt Miller had Brown at No. 26 on his big board in mid-December.) Instead, he's back for one more year with Auburn, and there's a good chance he'll be a preseason first-team All-American. The defensive tackle has racked up 105 tackles, 20 tackles for loss and 7.5 sacks over the past two seasons.

Synopsis

Four-year starter Dontavius Russell was a big loss for Auburn's defensive line, but it isn't an insurmountable one. The Tigers still have Brown, Nick Coe and Marlon Davidson, as well as other options for replacing Russell's production.

Auburn's problem figures to be the schedule. This is one of the most talented lines, but games against the offenses of Oregon, Texas A&M, Florida, LSU, Georgia and Alabama—six of the top 13 teams in USA Today's end-of-spring Top 25—would wear down anyone. Expect a lot of backfield penetration, but it's also probably fair to expect average marks in run defense against this slate.

7. LSU Tigers

Key players: Rashard Lawrence (54 tackles, 4.0 sacks), Glen Logan (46 tackles, 4.0 sacks), Neil Farrell Jr. (23 tackles, 1.5 sacks), Breiden Fehoko (16 tackles, 1.5 sacks), Tyler Shelvin (9 tackles, 1.5 sacks), Siaki Ika (true freshman), Jarell Cherry (redshirt freshman)

The star

It took a few years longer than expected, but 2016 5-star recruit Rashard Lawrence blossomed into something special over the latter half of last season. In the three-game stretch against Georgia, Mississippi State and Alabama, Lawrence accumulated 20 tackles. And between the regular-season finale against Texas A&M and the Fiesta Bowl against UCF, he had six tackles for loss and three of his four sacks for the season. If he can continue to build on that, look out.

Synopsis

If you're buying stock in LSU as one of the better defenses in the 2019 season, safety Grant Delpit is the biggest reason why. But this Lawrence-led line might end up being the bigger story by the end of the year.

With the exception of Ed Alexander—a defensive tackle who wasn't even selected in the NFL draft—the entire unit remains intact. The Tigers are also adding a top-200 recruit from last year's class (Jarell Cherry) and a top-150 player from this year (Siaki Ika), making improvement seem almost inevitable. Expect sophomore Tyler Shelvin to become a major factor at nose tackle.

6. Syracuse Orange

Key players: Alton Robinson (39 tackles, 10.0 sacks, 3 forced fumbles), Kendall Coleman (32 tackles, 10.0 sacks), Kingsley Jonathan (21 tackles, 5.0 sacks), Tyrell Richards (16 tackles, 3.0 sacks), Kenneth Ruff (19 tackles, 2.0 sacks), McKinley Williams (17 tackles), Josh Black (14 tackles)

The star

Both Alton Robinson and Kendall Coleman racked up 10 sacks last year and will return as seniors. It's hard to call either one a bigger star than the other, but Coleman had two sacks and seven total tackles against Clemson, as well as three sacks in the Camping World Bowl win over West Virginia. In Syracuse's biggest games, he was the bigger factor.

Synopsis

If Syracuse isn't the first team that comes to mind when thinking about defense, you aren't alone. In 2016, the Orange had one of the worst defenses in the nation, allowing more than 500 yards per game. But how could we not include a team that has two returning players with double-digit sacks last year?

Anchored by Robinson, Coleman and—to a lesser degree—Kingsley Jonathan, the Orange ranked sixth with 3.31 sacks per game in 2018. They're in a great position to repeat that feat, even though their overall defense may suffer from the departure of leading tacklers Ryan Guthrie and Kielan Whitner. Aside from the home game against Clemson, though, Syracuse doesn't face any elite offenses. As such, this unit should put up great numbers.

5. Penn State Nittany Lions

Key players: Yetur Gross-Matos (54 tackles, 20 tackles for loss, 8.0 sacks, 2 forced fumbles), Robert Windsor (39 tackles, 7.5 sacks), Shaka Toney (23 tackles, 5.0 sacks), PJ Mustipher (14 tackles), Antonio Shelton (14 tackles), Daniel Joseph (12 tackles, 1.0 sacks), Jayson Oweh (4 tackles, 2.0 sacks; redshirt freshman)

The star

Only two defensive linemen who recorded at least 18 tackles for loss last season are returning to college: Michigan State's Kenny Willekes and Penn State's Yetur Gross-Matos. YGM started slow, but he had 16 tackles for loss in the final seven games of the regular season, including a four-game streak with at least one sack. It was a sophomore-year breakout on par with what Aaron Maybin did for Penn State more than a decade ago.

Synopsis

The Nittany Lions lost two key linemen in Shareef Miller and Kevin Givens—a combined 74 tackles and 12.5 sacks in 2018—but the national leaders in sacks per game (3.62) can still bring it. Fifth-year senior Robert Windsor is one of the best penetrating defensive tackles in the game, and redshirt freshman Jayson Oweh should be near the top of everyone's list of potential breakout sensations.

Don't forget about Micah Parsons, either. The No. 5 overall recruit in last year's class is technically a linebacker now, but he was an edge-rushing machine in high school. Even though he doesn't count as a defensive lineman, he'll draw a lot of attention, allowing the actual linemen to benefit.

4. Alabama Crimson Tide

Key players: Raekwon Davis (55 tackles, 1.5 sacks), LaBryan Ray (39 tackles, 2.5 sacks), Phidarian Mathis (18 tackles), Stephon Wynn Jr. (3 tackles), Tevita Musika (3 tackles), Antonio Alfano (true freshman), DJ Dale (true freshman), Byron Young (true freshman), Ishmael Sopsher (true freshman)

The star

Alabama could have lost its entire starting defensive line, but Raekwon Davis opted to stick around for one more season. His 2018 numbers were a disappointment compared to what he accomplished as a sophomore (69 tackles, 8.5 sacks, one interception), which may explain why he's still in Tuscaloosa. Look for him to bounce back, becoming a surefire first-round draft pick and a possible All-American.

Synopsis

Alabama has some unknowns at defensive tackle after losing both Quinnen Williams and Isaiah Buggs to the NFL, but let's not pretend the Crimson Tide are lacking for talent. Nick Saban signed seven defensive linemen rated in the top 175 overall in this year's class, and DJ Dale—who had an impressive spring as an early enrollee—wasn't even one of them.

One big thing to keep in mind with Alabama is that the outside linebackers are effectively part-time defensive ends. Anfernee Jennings, Terrell Lewis and Eyabi Anoma are all candidates to lead the Crimson Tide in sacks, just like linebacker Christian Miller (8.5 sacks) almost did last year. 

3. Clemson Tigers

Key players: Xavier Thomas (35 tackles, 3.5 sacks), Justin Foster (18 tackles, 2.0 sacks), Nyles Pinckney (23 tackles), Jordan Williams (11 tackles, 1.5 sacks), Xavier Kelly (8 tackles, 1.0 sacks), Logan Rudolph (11 tackles), K.J. Henry (6 tackles; redshirt freshman), Justin Mascoll (redshirt freshman), Tyler Davis (true freshman)

The star

The Tigers don't have a returning starter on the defensive line, but Xavier Thomas got a lot of great experience as the fifth man behind Clelin Ferrell, Christian Wilkins, Dexter Lawrence and Austin Bryant. The No. 3 overall recruit in last year's class averaged 20 snaps per game and recorded multiple tackles in the ACC title game as well as in both of Clemson's College Football Playoff games. He will immediately become the leader and anchor of this group as a sophomore.

Synopsis

Clemson had three defensive linemen go in the first 17 picks of the 2019 draft, and a fourth was taken in the fourth round. But do you know who didn't go to the NFL? Defensive coordinator Brent Venables, who has coached the Tigers to five consecutive seasons with at least 45 sacks.

Clemson led the nation in yards allowed per carry and ranked second in sacks per game last year. Given how well head coach Dabo Swinney has been able to recruit and develop defensive linemen in recent years, we almost have to assume more of the same is on the horizon. There aren't any household names on the roster yet, but Thomas, Justin Foster, Jordan Williams and K.J. Henry will be well-known commodities in short order.

2. Utah Utes

Key players: Bradlee Anae (51 tackles, 15.5 tackles for loss, 8.0 sacks), Leki Fotu (33 tackles, 3.0 sacks), John Penisini (38 tackles, 2.0 sacks), Maxs Tupai (32 tackles, 3.0 sacks), Mika Tafua (23 tackles, 2.0 sacks), Hauati Pututau (19 tackles, 1.0 sacks), Pita Tonga (12 tackles, 2.5 sacks)

The star

Most teams are lucky to have either an outstanding pass-rushing defensive end or an outstanding lane-clogging defensive tackle, but Utah has one of each. DE Bradlee Anae and DT Leki Fotu could have bypassed their upcoming senior seasons to jump to the NFL. Instead, they decided to return in hopes of completing some unfinished business: getting Utah its first Pac-12 conference championship.

Synopsis

Utah did not lose a single noteworthy lineman from a group that ranked fifth nationally in both yards allowed per carry and rushing yards allowed per game. The Utes also tallied 37 sacks in 2018, tied for 19th-most. It seems safe to expect them to win the battles in the trenches once again.

The wild card is the linebacking group. Cody Barton and Chase Hansen anchored this defense with a combined 231 tackles last year, including 33.5 for loss and 9.0 sacks. The Utes lost both of them, but they've reloaded via the transfer market with Manny Bowen (Penn State) and Mique Juarez (UCLA). If those once-highly touted linebackers are able to thrive in Salt Lake City, it'll make the defensive line that much better.

1. Michigan State Spartans

Key players: Kenny Willekes (78 tackles, 8.5 sacks), Raequan Williams (53 tackles, 2.0 sacks), Jacub Panasiuk (31 tackles, 2.0 sacks), Naquan Jones (26 tackles, 2.0 sacks), Mike Panasiuk (25 tackles, 1.5 sacks)

The star

Much like Utah, Michigan State has the best of both worlds in edge-rusher Kenny Willekes and defensive tackle Raequan Williams. If the former makes a full recovery from the broken leg he suffered in the Redbox Bowl, both are strong candidates for preseason All-American consideration. They combined for 31 tackles for loss as juniors and should be the best defensive line duo in the nation as seniors.

Synopsis

Not only did Michigan State lead the nation in rushing yards allowed per game last season, but its average (77.9 YPG) was the lowest non-Alabama total since 2009. It was the fourth time in the past six seasons that the Spartans ranked either No. 1 or No. 2 in rushing yards allowed per game. And with the exception of backup defensive tackle Gerald Owens (24 career tackles), they get back every remotely noteworthy lineman.

Michigan State doesn't dominate with sacks like most of the teams featured here, but trying to establish the run against this brick wall is a fool's errand. If the Spartans offense can figure out how to average better than last year's putrid 18.7 points per game, this defense will make them a factor in the Big Ten championship race.

Kerry Miller covers college football and men's college basketball for Bleacher Report. You can follow him on Twitter, @kerrancejames. Recruit ratings courtesy of 247Sports' composite rankings.