One of the tough things about college football is that players only have four years of eligibility. Sometimes, top athletes don’t even stay that long, bolting for the NFL after only three seasons.

Unlike the NFL, where players can continue playing for the same team for years, the college ranks have a lot of turnover.

Unfortunately for college coaches, that means that sometimes a star player will either graduate or turn pro the year before they could really make an impact for their school.

Here’s one player that each of the 14 SEC teams wishes was still around as the 2017 season draws closer:

Alabama: Jonathan Allen, DL

Every year, Alabama loses star players and every year, the Crimson Tide replace them with new 5-star commits. However, replacing a guy like Allen — one of the most versatile defensive linemen in college football history — will be a tough task.

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With Da’Shawn Hand’s recent DUI arrest looming over the start of the 2017 season, the Crimson Tide will need new players to step up immediately to replace Allen in the middle of the defensive line.

Arkansas: Rawleigh Williams III, RB

Losing Williams, who finished third in the SEC in rushing yards last year, was one of the toughest situations of the offseason, as the star back injured his neck for the second time in his career and decided to retire.

Though the Razorbacks have Devwah Whaley to step in as the starter and landed David Williams as a graduate transfer from South Carolina, they’ll still miss the back who ran for 1,360 yards and 12 touchdowns in 2016.

Auburn: Carl Lawson, DE

Lawson had 9.5 sacks and 14.5 tackles for loss in 2016, marks that will be tough for Marlon Davidson and Byron Cowart to match this year.

With the Auburn offense set to take a big step forward under QB Jarrett Stidham, it’s unfortunate for coach Gus Malzahn that the defense will likely have more trouble getting after opposing quarterbacks without Lawson.

Florida: Jarrad Davis, LB

As usual, the Gators will be stacked in the secondary this year, even after Marcell Harris was lost for the season with an injury.

However, the linebacking corps will be thinner this season after Davis was selected by the Detroit Lions in the first round of the 2017 NFL Draft and Alex Anzalone went in the third round to the New Orleans Saints.

Having Davis back would have been a big help for first-year defensive coordinator Randy Shannon.

Georgia: Isaiah McKenzie, WR

The Bulldogs have some promising young receivers joining the team this season, notably 2017 commit Jeremiah Holloman, but it would be a mistake to expect too much of them right off the bat.

It would have been nice if sophomore QB Jacob Eason had a veteran like McKenzie in the mix this fall to take some of the pressure off the younger guys.

Kentucky: Jeff Badet, WR

Just when it looked like QB Stephen Johnson was ready to take the offense to a new level in 2017, he lost his deep threat in Badet.

As a junior in 2016, Badet caught only 31 passes, but those 31 receptions went for 670 yards and four touchdowns — an impressive average of 21.6 yards per catch. Now, he’ll make those big plays for Oklahoma after announcing this offseason that he was joining the Sooners as a graduate transfer.

LSU: Jamal Adams, S

The Tigers watched as RB Leonard Fournette (No. 4), S Jamal Adams (No. 6) and CB Tre’Davious White (No. 27) were selected in the first round of the 2017 NFL Draft, and LSU will miss all three. However, LSU has RB Derrius Guice coming back after he led the SEC with 1,387 rushing yards last year, so Fournette’s loss won’t be quite as hard to swallow.

Losing Adams, who was the quarterback of the defense, will be much tougher. Senior safeties Ed Paris and John Battle have their work cut out for them this fall as the Tigers wait for some talented young freshmen to get ready for starting jobs.

Mississippi State: Fred Ross, WR

If QB Nick Fitzgerald is going to improve as a passer this fall, he’ll have to do so without Mississippi State’s all-time leading receiver.

Ross, who tied for the SEC lead with 12 touchdown catches in 2016, is now a member of the Carolina Panthers and Donald Gray will need to pick up the slack for his redshirt junior quarterback or the offense will take a step back.

Missouri: Michael Scherer, LB

Yes, the Tigers also lost star DE Charles Harris from last year’s team, but they have Marcell Frazier and Terry Beckner Jr. to help fill that void along the defensive line.

The linebacking corps, on the other hand, is in much worse shape. Mizzou could really use Scherer, who was a tackling machine during his time in Columbia, roaming the field this fall.

Ole Miss: Evan Engram, TE

Chad Kelly had the benefit of throwing to Engram during the past couple of years in Oxford, but sophomore QB Shea Patterson won’t have that same safety net.

Engram was one of the most talented receivers in the entire conference last season and the promising young quarterback certainly could have used Engram’s skills.

South Carolina: Elliott Fry, K

Fry, who started for the Gamecocks all four years he was in Columbia, became the school’s all-time leading scorer last November.

The Gamecocks will turn to redshirt freshman Alexander Woznick this fall, but they’ll certainly miss Fry’s consistency, as it will be tough for Woznick to match Fry’s 76.5 percent (13-of-17) mark on field goals this year.

Tennessee: Joshua Dobbs, QB

This one is a no-brainer, which is ironic because Dobbs was one of the smartest players in the SEC. Yes, the Vols will miss DE Derek Barnett, LB Jalen Reeves-Maybin and DB Cam Sutton, but Dobbs ran the show offensively.

Whether he was throwing or running, Dobbs was in control of the Tennessee offense and will be very tough to replace. No matter who wins the starting job between Quinten Dormady and Jarrett Guarantano, they probably won’t bring everything Dobbs brought to the table.

Texas A&M: Trevor Knight, QB

The Texas A&M defense was hit hard by the loss of DEs Myles Garrett (the 2017 No. 1 overall pick) and Daeshon Hall (a third-round pick), but losing Knight will have a much bigger effect this season.

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With coach Kevin Sumlin on the hot seat heading into 2017, the Aggies will turn to senior Jake Hubenak as the starting quarterback. If Hubenak can’t get the ball to star WR Christian Kirk and take pressure off RB Trayveon Williams and the running game, it could be a long year in College Station.

Vanderbilt: Zach Cunningham, LB

Cunningham led the SEC with 125 tackles (71 of which were solo) in 2016 and was seemingly everywhere on the field.

As one of the best players in Vanderbilt history, Cunningham will be nearly impossible to replace. He was the first unanimous first-team All-American in school history. Players like that don’t exactly grow on trees in Nashville the way they do in Tuscaloosa.