Each week, Sports on Earth is counting down the best returning college football players at every position entering the 2017 season. These rankings are based on a combination of talent, proven production and potential at the college level. They are not NFL Draft rankings. This week, it's the top 35 offensive linemen.

Only two offensive linemen were picked in the first round of the NFL Draft in April, and both were somewhat off the radar entering the 2016 season: Garett Bolles and Ryan Ramczyk. Offensive line is a notoriously difficult position to evaluate and project, and there are sure to be plenty of wild cards this season. Nevertheless, our 2017 preseason college football player rankings continue with the top 35 returning linemen, all grouped together regardless of position.

2017 Sports on Earth college player rankings: Wide Receivers/Tight Ends | Linebackers | Running Backs | Defensive Linemen

35. Kyle Bosch, G, West Virginia. Bosch had an injury scare in the spring, but after what coach Dana Holgorsen called a "minor lower-body procedure," he's expected to be ready for the season. The Mountaineers need him. The offensive line has become a strength of the team, but the right guard is one of only two returning starters on the unit. A Michigan transfer, Bosch has started all 26 games in his West Virginia career.

34. James Daniels, C, Iowa. After acting as a rotational player as a true freshman, Daniels broke into the starting lineup at center last season, blocking for two 1,000-yard rushers -- including his older brother, LeShun Daniels. The junior center was voted third-team All-Big Ten and teams with guard Sean Welsh to form a potentially dominant duo on the interior of what should be another standout Hawkeyes offensive line.

33. Geron Christian, T, Louisville. Few units face more pressure this season than the Louisville offensive line, which was exposed late last season as the Cardinals stumbled to three losses in their final three games despite Lamar Jackson's Heisman win. Jackson needs more help from his front five this year, particularly on the interior. The biggest strength for the Cardinals there is left tackle thanks to Christian, the 6-foot-4, 318-pound junior who has started all 26 games in his career and was named third-team All-ACC as a sophomore.

32. Brian Allen, C/G, Michigan State. Allen -- the younger brother of former Spartans All-American Jack Allen -- has played both guard and center in his career and now he returns for his senior season as the veteran of an otherwise youthful offensive line and all-around uncertain offense. He has 25 career starts and is coming off an All-Big Ten season in which, according to Michigan State, he had twice as many knockdown blocks as anyone else on the team.

31. Wyatt Teller, G, Virginia Tech. The 308-pound Teller enters his fifth season with 30 career starts, quickly shifting from defensive line to offensive line at the start of his Virginia Tech career. It's a move that's paid off for both Teller and the Hokies, as he's become the leader of the offensive line at left guard, a physical blocker who excels on the move.

Left guard, No. 57

30. Tony Adams, G, N.C. State. The leader on the Wolfpack line with 35 career starts, Adams is coming off a second-team All-ACC season in which he shined as part of a group that allowed just 17 sacks in 13 games -- none of which were his responsibility, according to N.C. State. The 6-foot-2, 300-pound senior was instrumental in Matt Dayes becoming N.C. State's first 1,000-yard rusher since 2002.

29. Bradley Bozeman, C, Alabama. This spot could also go to junior left guard Ross Pierschbacher, but we'll highlight Bozeman, a 6-foot-5, 319-pound senior who had the impossible task of replacing Ryan Kelly in the middle of the Alabama line last season. Bozeman started all 15 games, developing into a reliable blocker for a prolific Crimson Tide ground attack. Alabama centers have won the Rimington Trophy in two of the past five seasons, and Bozeman will emerge as a candidate in 2017.

28. Jeromy Irwin, T, Colorado. The most valuable lineman on what proved to be a stellar Buffaloes O-line, Irwin has overcome injuries -- including a torn ACL that cost him most of 2015 -- to emerge as an All-Pac-12 player. In Colorado's breakthrough season, Irwin helped pave the way for Phillip Lindsay's 1,200-yard rushing season -- the program's first thousand-yard rusher since 2010 -- and he'll enter the 2017 season as a two-time team captain.

27. Greg Little, T, Ole Miss. The Rebels have signed the nation's No. 1 offensive tackle recruit in two of the past five classes. First it was Laremy Tunsil in 2013. Then it was Little in 2016. Controversy aside, Tunsil lived up to the recruiting hype as an All-American and three-year starter for the Rebels. Now, the pressure is on Little to make a leap as a sophomore at Tunsil's old position after easing his way into the lineup his first year. The 6-foot-6 Little played all year and started five games in the 2016 season, said he lost 20 pounds to around 320 and is the favorite the to protect the blind side of another highly recruiting rising star in QB Shea Patterson. He wasn't the instant star that Tunsil was, but he's a strong breakout candidate.

26. Martez Ivey, T/G, Florida. The No. 2 overall recruit in the class of 2015, according to the 247Sports composite rankings, Ivey broke into the starting lineup as a true freshman and emerged as the best player last season on what had been a problematic offensive line, voted second-team All-SEC by the conference's coaches and twice named SEC offensive lineman of the week. A guard the past two seasons, the 6-foot-5, 302-pound junior is moving out to left tackle.

25. Beau Benzschawel, G, Wisconsin. Ryan Ramczyk became the biggest star on the Wisconsin offensive line last season, but Benzschawel enjoyed a breakthrough of his own. After starting half his redshirt freshman season in 2015, Benzschawel emerged as a second-team All-Big Ten player at right guard last season. The Badgers and coach Paul Chryst are known for the ability to develop offensive linemen, and Benzschawel is set to be the next big thing.

24. Tyrell Crosby, T, Oregon. A rising star entering last season, Crosby unfortunately saw his season cut short in September because of a foot injury. He's now the veteran of a sophomore-dominated offensive line that should be much-improved this season, and his decision to return to the Ducks at left tackle is massive for this offense. He's a building block for an offense that will be explosive in Willie Taggart's first season as head coach.

23. Scott Quessenberry, C, UCLA. Despite the Bruins' significant offensive line issues, Quessenberry stood out in the middle of the line to earn first-team All-Pac-12 honors from the conference's coaches. After mostly playing guard in 2014, Quessenberry sat out the 2015 season while recovering from shoulder surgeries. He returned to the lineup as the center last season, and he'll anchor a unit facing a lot of pressure to better protect QB Josh Rosen and help revive the run game.

22. Jamarco Jones, T, Ohio State. A high-profile recruit, Jones broke into the starting lineup as a junior last season and became a second-team All-Big Ten pick as the Buckeyes' starting left tackle. While there were a few down moments for both Jones and the Buckeyes' line as a whole in pass protection, the 6-foot-5, 310-pound Jones has clear pro potential and has grown into a star who gives Ohio State confidence that J.T. Barrett will be well protected in his senior season.

21. Ryan Bates, T/G, Penn State. Offensive line has been a post-NCAA sanctions weakness for Penn State, but after showing signs of improvement last year, the unit is ready to become a formidable one this fall -- so much so that it's unclear who will play where because depth has grown to the point where there are options at every spot. One thing that is clear is there will be a starting spot for Bates, whether it's at guard or tackle. As a redshirt freshman, Bates started all 14 games, rotating between left guard and left tackle as Penn State dealt with injuries. Wherever he ends up, Bates quickly become a reliable blocker in both the running and passing games, and he's poised for a breakout to All-Big Ten status as a sophomore.

Left tackle, No. 52

20. Mason Cole, T/C, Michigan. The versatile Cole earned a starting job instantly upon his arrival in Ann Arbor, spending his first two seasons at left tackle. Last year, he moved inside to center and was named second-team All-Big Ten. The Wolverines have reshuffling to do on the line, and Cole's position is up in the air, but with 38 straight starts to his credit, Cole is poised to be the star of this line whether he moves back out to left tackle or stays in the middle.

19. Brian O'Neill, T, Pittsburgh. He is most famous for the that he scored two touchdowns last season, but O'Neill's status as America's favorite gadget-play lineman shouldn't overshadow his value to Pitt as a blocker. That'll be even truer this year as the Panthers say goodbye to stalwarts Dorian Johnson and Adam Bisnowaty. Both of them were first-team All-ACC picks. O'Neill, a second-team pick, is a former tight end who bulked up to 300 pounds and started all 13 games as a tackle.

18. Chukwuma Okorafor, T, Western Michigan. Coach P.J. Fleck, quarterback Zach Terrell and receiver Corey Davis are all gone, but there is still a lot of talent on this roster from a team that went to the Cotton Bowl, particularly in the ground game. Okorafor moved to the United States from Botswana in 2010, and, despite not taking up football until his sophomore year of high school, he has developed into an NFL prospect. The 6-foot-6, 330-pound senior has 27 career starts, and he was the left tackle last year for a line that allowed just 16 sacks in 14 games.

17. Will Clapp, C, LSU. Honored as a first-team All-SEC pick by the league's coaches last season, Clapp has played an integral role in the running success of Leonard Fournette and Derrius Guice. He'll continue to blow open holes for the latter this season, likely at center instead of guard as he shifts over to replace Ethan Pocic. Clapp started 12 games as a redshirt freshman in 2015 and continued his upward trajectory last season, and now he'll be expected to stand out as the star in the middle of the Tigers' line under new offensive coordinator Matt Canada.

16. Sean Welsh, G, Iowa. The Hawkeyes' line continues to enjoy a sterling reputation, and Welsh is the leader of a stellar group that returns four starters to block for rising star tailback Akrum Wadley. A third-team All-Big Ten performer last season, Welsh is a 6-foot-3, 288-pound senior, a physical player who is the star of a unit that was honored for its performance as a whole, winning the 2016 Joe Moore Award as the nation's top O-line.

15. Tyrone Crowder, G, Clemson. A powerful mauler in the running game, Crowder is coming off a first-team All-ACC season at right guard. The 6-foot-2, 340-pound senior has 28 career starts, and he's the Tigers' biggest asset on the ground as they try to replace the rushing production of Wayne Gallman and QB Deshaun Watson.

14. Martinas Rankin, T/C, Mississippi State. Big things are expected of the 6-foot-5, 302-pound senior. A juco transfer, Rankin redshirted in 2015, then broke into the starting lineup last season with 10 starts at left tackle. He actually played some center during the spring, meaning his position on the line is up in the air. Rankin and the line as a whole dealt with some growing pains last year, but he's emerging as a star, blocking for a QB in Nick Fitzgerald who rushed for 1,375 yards.

13. Dalton Risner, T, Kansas State. After starting 13 games at center as a redshirt freshman, Risner moved outside to right tackle as a sophomore and was voted first-team All-Big 12. He played a key role in the Wildcats' substantial improvement on the ground, and he's the leader of a solid offensive line that will open the door for an even more productive running game this fall.

12. Mitch Hyatt, T, Clemson. The Tigers coaching staff entrusted Hyatt with protecting the blind side of Deshaun Watson -- the most valuable player in school history -- each of his first two years on campus. A five-star recruit, Hyatt has lived up to the recruiting hype, starting 29 games in his career already and earning freshman All-America honors in 2015 and All-ACC honors in 2016. Like the Clemson O-line as a whole, Hyatt's performance hasn't been entirely consistent, but he's played an integral role in this offense's success and should be coveted in the NFL Draft as he continues to develop.

11. Jonah Williams, T, Alabama. Cam Robinson started from Day 1 at left tackle at Alabama, starring for three years. Williams is poised to follow a mostly similar path. Like Robinson, he started as a true freshman. However, he was on the right side last year. Now, with Robinson off to the NFL, the 6-foot-5, 296-pound five-star recruit will shift to the left side, a move likely to be a smooth transition for a player who looked far older than a freshman last season.

10. Cody O'Connell, G, Washington State. O'Connell enjoyed a meteoric rise last season, as the 6-foot-8, 354-pounder went from two years without playing to playing sparingly as a redshirt sophomore to earning All-America honors and being an Outland Trophy finalist as a junior. It was a staggering breakthrough season for the left guard, who plays a key role in keeping prolific quarterback Luke Falk upright in this pass-happy Wazzu offense.

9. Will Hernandez, G, UTEP. The former offensive line coach of the Pittsburgh Steelers and Buffalo Bills, Miners head coach Sean Kugler has tried to build a physical, run-first program in El Paso. Success has mostly come from tailback Aaron Jones, who rushed for 1,773 yards last year, averaging 7.7 yards per carry. He had a lot of help from Hernandez, a nasty, overpowering blocker who has started 37 career games at left guard and won first-team All-Conference USA honors last season. He's a legitimate All-America candidate, just as Forrest Lamp at conference foe Western Kentucky was last year.

Left guard, No. 76

8. Quenton Nelson, G, Notre Dame; and 7. Mike McGlinchey, T, Notre Dame. The left side of the Notre Dame offensive line is dominant, with McGlinchey and Nelson teaming up as a formidable duo that is as good as any tackle-guard combination in college football. Nelson is a 6-foot-5, 329-pound redshirt junior, and McGlinchey is a 6-foot-8, 312-pound senior. Both could have turned pro last year, but they're back bringing tenacity to the Irish line, particularly in the run game.

6. Trey Adams, T, Washington. A couple years ago, Adams, quarterback Jake Browning and running back Myles Gaskin were freshman starters, leaders of a green, work-in-progress offense. Now they're junior cornerstones returning to a playoff team that has hopes of winning another Pac-12 title. A four-star recruit, Adams has started 23 games in his two seasons at Washington, becoming a first-team All-Pac-12 performer as a sophomore left tackle for one of the nation's most efficient offenses.

Left tackle, No. 72

5. Braden Smith, G/T, Auburn. The Tigers' offensive line had a rock-solid season last year, paving the way for what developed back into a prolific running back with Kamryn Pettway and Kerryon Johnson. Smith enters the 2017 season having made 27 straight starts, mostly at guard. However, the 6-foot-6, 303-pound senior played right tackle in the spring. Wherever he is on the line, Smith has developed into one of the most reliable blockers in the SEC, a physical and relentless player.

Right guard, No. 71

4. Frank Ragnow, C, Arkansas. Bret Bielema's bread and butter is typically offensive line play, and while the Razorbacks gave up too many negative plays last season, there is no problem in the middle: Ragnow is a star, a 6-foot-5, 319-pound senior with experience at guard and center and 35 career starts, proving to be a tough, sturdy and reliable anchor for the Hogs in the middle.

3. Orlando Brown, T, Oklahoma. The Sooners will have an experienced line that ranks among the best units in the country this season, and a big reason for the latter is the presence of Brown. The son of longtime NFL lineman Orlando Brown, the 6-foot-8, 360-pound junior has started 26 games at left tackle, protecting the blind side of Heisman finalist QB Baker Mayfield. Massive and overpowering, Brown was voted Big 12 offensive lineman of the year as a sophomore.

Left tackle, No. 78

2. Billy Price, C, Ohio State. A year ago, established star Pat Elflein returned to Ohio State for his senior season and moved from guard to center, a smooth transition that resulted in the Rimington Trophy. Price is hoping to follow that model After 41 straight starts at guard and earning All-America honors as a junior, Price is moving to center for his fifth season, where the All-America nods should continue.

1. Connor Williams, T, Texas. The Longhorns offensive line was a weakness at the start of the Charlie Strong era, but by the end it became the least of the team's concerns. Led by Williams, the Texas offensive line paved the way for D'Onta Foreman's 2,000-yard season on the ground. Texas did give up 32 sacks, but that's not unusual with a freshman quarterback. Williams is the clear leader up front, a freshman All-American in 2015 and first-team All-American in 2016 who has started at left tackle since his first game. He's as technically sound and reliable as it gets up front, and his presence will make the transition to Tom Herman's offense much easier.

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