Not surprisingly, many of last season's biggest stars are among the top prospects in Mel Kiper Jr.'s latest mock draft. While they await a new team, their old teams will have to find replacements for them.
Here's a look at some of the top replacement candidates:
USC Trojans
Who they're losing: QB Sam Darnold
How they'll replace him: This was the year Darnold originally was supposed to take over for Max Browne. Instead of preparing for his first year as the Trojans starter, Darnold could very well end up the No. 1 pick in the draft, leaving USC's succession plan unclear. Redshirt sophomore Matt Fink, redshirt freshman Jack Sears and true freshman J.T. Daniels, who is skipping his senior year of high school and arrives in the summer, are the three options. Fink is best positioned to win the job because of experience, but he has attempted only nine career passes. -- Kyle Bonagura
UCLA Bruins
Who they're losing: QB Josh Rosen
How they'll replace him: Devon Modster played well in relief of Rosen in 2017 and is probably the favorite, but with a new coach in Chip Kelly, the head start he had in the competition to replace Rosen isn't as significant. The other two scholarship quarterbacks from last year's team, Matt Lynch and Austin Burton, will be joined by K.J. Carta-Samuels, a graduate transfer from Washington, and true freshman Dorian Thompson-Robinson. Thompson-Robinson has star potential, but he'll have a lot of catching up to do because he won't be on campus for spring practice. -- Bonagura
Penn State Nittany Lions
Who they're losing: RB Saquon Barkley
How they'll replace him: Penn State realizes Barkley is an all-time program great, but it has a solid succession plan. Miles Sanders was a more decorated recruit than Barkley -- ESPN's No. 3 running back and No. 43 overall player in the 2016 class -- and averaged 6.2 yards per carry in limited work last season. Penn State just signed Ricky Slade, ESPN's No. 2 back and No. 17 overall player in the 2018 class. Coaches think Slade can work his way into the rotation right away. Redshirt freshman Journey Brown adds an elite speed threat to the backfield. -- Adam Rittenberg
Oklahoma Sooners
Who they're losing: QB Baker Mayfield
How they'll replace him: The offseason battle to replace Mayfield will be between juniors Kyler Murray and Austin Kendall, but Murray appears to be the front-runner. The transfer from Texas A&M was the primary backup last season, threw 21 pass attempts (completed 18, including three touchdowns) and had offensive packages designed for his running ability (he had 14 carries for 142 yards). A lot of eyes will be on Murray, a former five-star recruit who was one of the most decorated quarterbacks in Texas high school football history, with three state championships and a 42-0 record. -- Sam Khan Jr.
Who they're losing: OT Orlando Brown
How they'll replace him: The Sooners have some quality depth up front, which will ease the loss of Brown. Bobby Evans, a junior who has 26 career starts under his belt (all of them at right tackle, including all 14 last year) is a likely option to slide to the left side to succeed Brown. The Sooners are also in the mix for Rice graduate transfer offensive tackle Calvin Anderson, who will decide on his 2018 destination soon. -- Khan
Alabama Crimson Tide
Who they're losing: DB Minkah Fitzpatrick
How they'll replace him: Losing all four starters in the secondary and six players overall will be an issue. But talented underclassmen Deionte Thompson and Daniel Wright had meaningful playing time last season, and coach Nick Saban and his staff clearly made the position a priority on the recruiting trail, signing No. 1 cornerback and five-star Patrick Surtain Jr., and No. 1-ranked junior college cornerback Saivion Smith. -- Alex Scarborough
Who they're losing: WR Calvin Ridley
How they'll replace him: The Tide had a real problem in terms of spreading the wealth in the passing game last season. It was like Calvin Ridley and the Pips the way the spotlight stayed focused on one person. But Alabama's backup singers finally showed up during in the national championship game with freshman studs DeVonta Smith, Henry Ruggs III and Jerry Jeudy making plays and showing their potential in what would turn out to be Ridley's final game. -- Scarborough
Georgia Bulldogs
Who they're losing: Roquan Smith
How they'll replace him: If Kirby Smart is really building the Alabama of the SEC East, then this is where it will start to show. The Tide made a habit out of replacing one star middle linebacker with another, whether it was Rolando McClain or C.J. Mosley or Reuben Foster. Now it's the Bulldogs' turn with Smith, the Butkus Award winner, leaving some big shoes to fill for someone like Natrez Patrick or Nate McBride. -- Scarborough
Washington Huskies
Who they're losing: DL Vita Vea
How they'll replace him: Perhaps no team in the Pac-12 has replaced NFL talent as seamlessly as Washington in recent years, especially on defense. Vea's departure leaves a massive hole in the middle of the defensive line -- much like when Danny Shelton was drafted 12th overall in 2016 -- but the Huskies still should have one of the conference's best defensive fronts. DT Greg Gaines, who started every game and was a second-team All-Pac-12 selection, will play an even more important role, while Jaylen Johnson and Levi Onwuzurike return after gaining valuable experience in 2017. -- Bonagura
NC State Wolfpack
Who they're losing: DE Bradley Chubb
How they'll replace him: Not only do the Wolfpack lose leading sacker Chubb, but they also lose every starter on the defensive line. Still, this is a group that was so deep, coaches across the ACC believed their backups could be starters, too. Now is the time for defensive end Darian Roseboro to prove that. Roseboro turned down an opportunity to leave early for the NFL draft, and all eyes will be on him to become an every-down pass-rusher now that he has his opportunity. As a sophomore two years ago, he had seven sacks, and almost half his tackles were behind the line. -- David M. Hale
Ohio State Buckeyes
Who they're losing: DB Denzel Ward
How they'll replace him: Ward leaves a major void, which Ohio State hopes to fill with several options, including Jeffrey Okudah. ESPN's No. 7 recruit in the 2017 class played mostly special teams as a freshman but will compete with juniors Damon Arnette and Kendall Sheffield, who shared the top spot opposite Ward. Shaun Wade, another top-10 national recruit in 2017, is also in the mix. Jordan Fuller is back at one safety spot after starting 13 games last season. Isaiah Pryor is in line for the other starting spot, although the coaches will look to create more competition this spring. -- Rittenberg
Texas Longhorns
Who they're losing: OT Connor Williams
How they'll replace him: Even when Williams was on campus, tackle depth was a need for the Longhorns, and it's even more so now. There are several potential roster options but no heir apparent: Sophomore Derek Kerstetter, who started at right tackle, could switch to left tackle; Elijah Rodriguez, who started at left tackle in the Longhorns' bowl game, is an option, too. Coach Tom Herman signed three tackles in the 2018 class, including a junior college prospect, Mikey Grandy. The team is also in the market for a graduate transfer: Rice's Calvin Anderson, who has the Longhorns as one of his four finalists. If he heads to Austin, he would also compete for the job. -- Khan
Notre Dame Fighting Irish
Who they're losing: OL Quenton Nelson and OL Mike McGlinchey
How they'll replace them: Notre Dame's line will look different and younger, but it returns a cornerstone piece in center Sam Mustipher. The coaches like Alex Bars to remain the starting right guard. Tommy Kraemer edged out Robert Hainsey at right tackle last season and could now shift to left tackle, taking over for McGlinchey. Liam Eichenberg, ESPN's No. 67 overall player in the 2016 class, backed up McGlinchey but will compete with Hainsey for the starting right tackle spot. Josh Lugg is a big body (6-foot-7, 300 pounds) who played behind Nelson at right guard and is the heavy favorite to take over there. -- Rittenberg
Virginia Tech Hokies
Who they're losing: LB Tremaine Edmunds
How they'll replace him: Edmunds is such a big loss because he could do so much. But the Hokies lost everybody at linebacker, so expect the pass rush to come predominantly from the defensive line, which has more veterans returning. Watch for end Trevon Hill, who played well down the stretch a year ago and ended up tied with Edmunds for the team lead with 5.5 sacks. Houshun Gaines is another player to keep an eye on, and the Hokies hope he can build on the big game he had against Virginia in the regular-season finale when he had two tackles for loss and a fumble recovery. -- Hale