Every team in the country deals with roster turnover on an annual basis. Players graduate and move on, and then new players from high school come in to replace them. That's how it has always worked. What some teams have to cope with more than their counterparts, however, are the early departures.

You know a guy is going to leave after he runs out of eligibility, but players leaving early for the NFL Draft with eligibility remaining can throw off a team's plans. Even though coaches are smart enough to prepare for early departures -- it's not too hard to figure out which of your players will likely leave early -- they can still have a major impact on your roster when combining them with all the seniors you're already losing.

As a result, some teams are more affected more than others, and this year these are the teams hit hardest by early departures.
Florida St.
There will be a lot of changes in Tallahassee next season. With Jimbo Fisher leaving to take over at Texas A&M, it likely pushed a few players in the direction of leaving early, and as a result, the Seminoles will lose six to the NFL. Safety Derwin James, cornerback Tarvarus McFadden, defensive ends Josh Sweat and Jalen Wilkerson, wide receiver Auden Tate and tight end Ryan Izzo are all getting out of town. If there's any silver lining, it's that FSU's depth chart wasn't senior-heavy to begin with, but losing six key players is still losing six key players.
LSU
Like Florida State, LSU is also dealing with the loss of six players. Derrius Guice is the headliner of those leaving early, but Arden Key will likely be a first-round pick as well. Then you have two of your top corners in Donte Jackson and Kevin Toliver leaving. Oh, and you have two of your starting offensive linemen in William Clapp and Toby Weathersby departing. That means you're losing 60 percent of your offensive line as K.J. Malone is a senior. In fact, of the 11 starters on LSU's offensive depth chart this season, only three players will be returning -- five were seniors and three more are leaving early.
Alabama
Losing players early to the NFL is just a way of life with the national champions. You don't worry about Alabama's ability to replace them because they've done it so many times before, but you can't ignore the quality of talent this team is losing, either. Alabama loses five early this year, including Minkah Fitzpatrick, Ronnie Harrison and Da'Ron Payne on defense. On the other side of the ball, the Tide lose Calvin Ridley and Bo Scarbrough. With a stable of young running backs, the Scarbrough loss isn't too significant, but Ridley was the best receiving option on the team.
Texas
Tom Herman will have some transitioning to do during his second season in Austin. The Longhorns were led by their defense in 2017, and they'll have to replace a lot of it in 2018. Malik Jefferson led the team in tackles, DeShon Elliott led the team in interceptions, and both are leaving. As is cornerback Holton Hill and offensive tackle Connor Williams, though the latter missed most of the 2017 season, so at least Texas already has experience replacing him. Then there's punter Michael Dickson. You might not think a punter is important, but when you have one that's as good as Dickson, it's an impact that will be felt in 2018.
Auburn
Auburn had one of the best defenses in the country this season, and it's losing two of its biggest contributors in Jeff Holland and Carlton Davis. The good news is that most of Auburn's defense will return in 2018, but the secondary will have a new look. Davis' early departure combined with the graduations of both Stephen Roberts and Tray Matthews means the Tigers' defense will have three new starters in the back next season. Offensively, Auburn loses both Kerryon Johnson and Kamryn Pettway. Kam Martin will likely take over the starting spot at running back.
Stanford
The biggest early departure -- literally and figuratively -- is Harrison Phillips, who led the team in both sacks and tackles for loss. Simply put, he was a disruptive force on the defensive line. Other key losses are corner Quentin Meeks and safety Justin Reid. Those two leaving means Stanford will lose three-fourths of its secondary. The Cardinal also lose tight end Dalton Schultz, though I'm pretty sure Stanford has a Tight End Tree (or maybe they turn trees into tight ends given the size of them), so it can just pluck a new one.
Notre Dame
The Irish only have three early departures, but they're big ones, particularly when combined with losses elsewhere. Josh Adams is the biggest name because he just rushed for 1,430 yards, but he might also be the easiest to replace. Guard Quenton Nelson could be a top-10 pick, and his loss combined with the graduation of Mike McGlinchey means the entire left side of Notre Dame's offensive line is gone (as is OL coach Harry Heistand -- to the Chicago Bears). The Irish also lose their leading receiver Equanimeous St. Brown, who averaged 15.61 yards per reception this season.
Oklahoma
As if having to replace Baker Mayfield wouldn't be difficult enough, the Sooners lose three other key players. Left tackle Orlando Brown will be a first-round pick, and Mayfield's security blanket TE Mark Andrews is leaving as well. Defensive tackle Du'Vonta Lampkin is gone, which will effect Oklahoma's depth on the defensive line next year. This is a case where it's not the quantity but the quality of losses with Brown and Andrews in particular.
UCLA
Chip Kelly's first year with the Bruins will see him taking over an offense losing three key players. The biggest name is obviously Josh Rosen, who could be the first QB chosen in the NFL Draft. Aside from Rosen, the Bruins also lose Jordan Lasley, who led the team in receiving with 69 catches for 1,264 yards. Tackle Kolton Miller is also on his way out the door, meaning the Bruins will have to replace three offensive linemen.
USC
The good news for USC is that skill position talent is generally easier to replace than experienced offensive linemen. The bad news is that the three most important skill position players on USC's offense are all leaving early. Sam Darnold is the headliner for obvious reasons, but running back Ronald Jones and wide receiver Deontay Burnett are leaving too. That means the Trojans are losing their starting quarterback, leading rusher and leading receiver to the draft early. This is not an ideal position to be in.