ESPN College Football

The nature of college football is filling in positions for departing players.

But some Big 12 players will be facing bigger challenges than most.

Here's a look at the players who will be the toughest to replace across the Big 12:

1. Texas QB Colt McCoy: He leaves school as the most statistically proficient quarterback in school history, although his career will forever be marked by his near misses in the Heisman Trophy balloting over the past two seasons and his injury in his final college game against Alabama. Garrett Gilbert will be facing some big shoes to replace when Texas practice starts later this month.

2. Nebraska DT Ndamukong Suh: He will go down in history as arguably the greatest Blackshirt ever, a player who stayed in school for an extra season and cashed in with a haul of individual trophies. Terrence Moore will accept the huge challenge to replace the most dominant defensive force in Big 12 history and in recent college football history.

3. Oklahoma State CB Perrish Cox: His ability as a shutdown cornerback and a punt returner helped marked the Cowboys' defensive effort last season. Cox led the Big 12 with 19 passes defensed and he didn't play in his final game in the Cotton Bowl. Overachieving 5-foot-8, 180-pound Brodrick Brown will have the unenviable task of trying to replace Cox in the Cowboys' secondary.

4. Oklahoma DT Gerald McCoy: Although he was sometimes overshadowed by Suh in the conference, McCoy was the anchor of the Sooners' defense during the past three seasons, notching six sacks and 15.5 tackles for losses last season. Heralded Jamarkus McFarland will get the first shot at replacing McCoy -- not only in his production but also in his leadership.

5. Missouri WR Danario Alexander: The Tigers will bring back starters Jerrell Jackson and Wes Kemp, along with heralded rising sophomore T.J. Moe. But it still won't lessen the contributions of Alexander, who blossomed into the nation's top receiver over the second half of the season, finishing with school-record single-season totals of 113 receptions and 1,781 receiving yards.

After every season, starters leave. But not all starters are created equal.

Here are the biggest shoes to fill in the Pac-10 with spring practices just around the corner.

Toby Gerhart, RB, Stanford

How do you replace the best running back in the nation, a guy who scored 28 touchdowns and rushed for 1,871 yards? You don't. Those sorts don't come around every season.

The Contenders: Stepfan Taylor and Tyler Gafney will get first crack, as well as Jeremy Stewart, who's coming back from a knee injury. Incoming freshman Anthony Wilkerson could be a dark horse.

Sean Canfield, QB, Oregon State

The first-team All-Pac-10 quarterback became an NFL prospect during a strong senior season. He led the conference with 3,271 yards passing and 21 touchdowns, which tied with Washington's Jake Locker.

The Contenders: This will be a showdown between Ryan Katz and Peter Lalich this spring, with Katz starting as the leader.

Brian Price, DT, UCLA

Price could be an NFL first-round draft pick. He led the Pac-10 with 23.5 tackles for a loss in 2009. 'Nuff said.

The Contenders: Good question. The Bruins are perilously thin here, considering both tackles need to be replaced and only senior David Carter has much experience. The answers here might be in the Bruins' recruiting class.

Syd'Quan Thompson, CB, California

The Cal secondary was a huge disappointment this season, but Thompson, a four-year starter and two-time first-team All-Pac-10 performer, was mostly his usually stellar self.

The Contenders: Will Darian Hagan step up in his senior season? Perhaps the answer is sophomore Josh Hill? Or maybe a redshirt guy? The Bears only signed one player listed as a corner in their most recent recruiting class. Expect there to be a lot of competition here this spring.

Daniel Te'o-Nesheim, DE, Washington

Te'o-Nesheim, a high-motor guy who started four years and earned second-team All-Pac-10 honors his final two seasons, ranking third in the conference with 9.5 sacks.

The Contenders: Considering the other end, Darrion Jones, also is gone, the Huskies will trend young here. Andru Pulu was listed behind Te'o-Nesheim on the depth chart, with Talia Crichton and Kalani Aldrich on the other side. There also will be opportunities for younger players here.

Ed Dickson, TE, Oregon

Dickson not only was the Ducks' second-leading receiver with 42 receptions for 551 yards and six touchdowns, the matchup problems he presented forced defenses to scheme specifically for him. That helps an offense in ways that aren't accounted for in statistics.

The Contenders: Junior David Paulson was Dickson's backup last year, and he had some nice moments, but he's no Dickson. JC transfer Brandon Williams and touted incoming freshman Curtis White will be in the mix here.

Kenny Alfred, C, Washington State

Alfred, a four-year starter, was a good player on a bad -- and beaten up -- line. His brain as well as his physical ability will be hard to replace.

The Contenders: Walk-on junior Chris Prummer was listed as Alfred's backup -- largely due to injury -- but Andrew Roxas, who redshirted this year after contracting viral hepatitis, is probably the leader here, though Steven Ayers could move inside to challenge him. Or there could be some reshuffling.

Every year in the SEC, there are some big shoes to fill.

But next season, we're talking size 18s, 19s and 20s everywhere you look.

When you factor in the talented juniors leaving the conference, new faces, new leaders and new playmakers are going to have to step up like never before in 2010.

That said, here’s a look at the biggest shoes to fill in the league next season. As you might imagine, the names are familiar ones:

1. Florida quarterback Tim Tebow: Contrary to popular belief, Tebow didn’t play seven seasons at Florida. It just seemed that way to everybody he beat up on. As a starter, he was a remarkable 35-6 with a Heisman Trophy, one SEC championship, one BCS national championship, two SEC championship game appearances and two BCS bowl wins. He scored more touchdowns than anybody who’s ever played in the SEC, and he was the kind of inspirational leader that coaches dream about having on their team. It’s impossible to replace everything that Tebow was to the Gators. He’s one of the best college football players of this era. Junior John Brantley gets first chance. He’s a different kind of quarterback than Tebow and is already an extremely polished passer. The Gators’ offense will change with Brantley, a highly recruited player who’s been waiting for his chance.

2. Alabama linebacker Rolando McClain: One of the smartest players Nick Saban has ever coached, McClain was so many things, not only to the Alabama defense, but to the entire team. For one, he was that rock-solid, emotional leader all great teams have. But he was also that guy on the field who knew everybody’s position, knew everybody’s duties and made sure guys were in the right spots. On top of it all, the 6-foot-4, 255-pound McClain was one of the most productive linebackers in the country who was always making game-changing plays. With the Butkus Award winner deciding to turn pro early, Dont’a Hightower is the heir apparent to take over for McClain. Hightower is a great player in his own right, but is coming off reconstructive knee surgery. If he returns close to 100 percent, the Crimson Tide could have their second straight Butkus Award winner.

3. Mississippi State running back Anthony Dixon: We’re going with Dixon at the No. 3 spot for a couple of different reasons. Most importantly, it’s always a chore to replace 126.5 rushing yards per game. Dixon led the SEC in that category. But here’s the other thing: Dixon WAS the Mississippi State offense last season. Dan Mullen rode him the entire season, and Dixon delivered with a record-setting season. With him gone (along with two other senior running backs), the Bulldogs will have to tweak things some offensively in 2010. Making it even more difficult is that there’s not a proven quarterback on campus. Chris Relf was the Bulldogs’ designated runner at quarterback last season and was good in that role. But he only attempted 41 passes in 10 games. Redshirt freshman Tyler Russell will get every chance to win the quarterback job this fall. But when things get hairy, he won't have the luxury of turning around and handing the ball off to Dixon.

4. Ole Miss running back Dexter McCluster: Staying in the state of Mississippi, there wasn’t a more productive or feared player in the league during the second half of the season than McCluster. From the Arkansas game on (or once he moved full time to running back), he carved opposing defenses apart and made the Rebels’ offense so much better with his ability to strike from long distance. The Rebels didn't have to put together long drives all the time because the speedy McCluster was popping long runs left and right. There’s not player in this league, let alone on Ole Miss’ roster, just like McCluster. After all, he became the first player in SEC history to rush for 1,000 yards and have 500 yards receiving in the same season in 2009. It may be that the Rebels have to divvy up his roles next season. Junior Brandon Bolden returns as the featured back, but junior college newcomer Randall Mackey looks like a great fit in the Wild Rebel formation. And Ole Miss also needs to find more ways to get the ball to Jesse Grandy. The wild card is Tim Simon, who looked great early on as a freshman before suffering a nasty knee injury. His recovery could be a lengthy one.

5. Tennessee safety Eric Berry: Even though Berry’s interception numbers were down last season, he was still the most complete safety in college football. The Jim Thorpe Award winner was used mostly as a hybrid linebacker in Monte Kiffin’s defensive system and ended up leading SEC defensive backs with 87 tackles, including seven for loss. Having a safety the caliber of Berry opens up so many other things for your defense. He makes up for mistakes, takes the pressure off more unproven players in the secondary and forces the opposing offensive coordinator to know where he is at all times. Berry was perennially around the ball and made so many things happen for the Vols the past three years. Plus, he provided some invaluable leadership for that defense. Janzen Jackson has the physical talent to be the next great safety at Tennessee. When he wasn’t suspended last season, he made his presence felt as a freshman. But he still has to prove that he’s going to do the right things both on and off the field.

A year ago at this time, the Big East was dealing with the loss of a plethora of stars, including some of the best players in league history. Guys like Pat White, Donald Brown, Kenny Britt, LeSean McCoy and Scott McKillop seemed difficult, if not impossible, to replace.

The league fared just fine in 2009 without those stars, and the good news for 2010 is that many of its top performers will be back. But that's not to say there aren't still some key losses that teams will have to adjust to this spring. Here's a look at the biggest shoes to fill this season in the Big East:

• Mardy Gilyard, WR, Cincinnati: The Bearcats aren't exactly hurting at wide receiver with Armon Binns, D.J. Woods and USC transfer Vidal Hazelton around. Still, someone must replace Gilyard's leadership and knack for making the big play at crucial times. What might be even more difficult to replace is Gilyard's production on special teams. The two-time Big East special teams player of the year was always a threat to score on kickoffs and punt returns. And hopefully someone will step in Gilyard's role as the best quote in the entire conference.
• Tim Brown, WR, Rutgers: Brown may not have received a ton of attention nationally, but he was vitally important to the Scarlet Knights. The speedster averaged 20.9 yards per catch and amassed 1,150 receiving yards and nine touchdowns as the team's only true deep threat. With a still very young receiving corps surrounding Tom Savage, Rutgers will need to find someone who can stretch the field the way Brown did.
• Mick Williams, DT, Pittsburgh: The 2009 co-defensive player of the year in the conference, Williams was a wildly disruptive force in the middle of that Panthers defensive line, as well as an inspirational leader. With fellow senior tackle Gus Mustakas also gone, Pitt needs more production from backups Myles Caragein and Chas Alecxih, among others.
• Devin McCourty, CB, Rutgers: McCourty was an underappreciated gem for the Scarlet Knights, a lockdown cornerback who also was seemingly everywhere on special teams. He was the leader of the secondary. Guys with his skills don't come around that often.
• Reed Williams, LB, West Virginia: The Mountaineers had to deal with Williams' absence for most of 2008 and at times this past season because of various injuries. But it was clear that they were a different team whenever Williams was healthy. A smart player (he's the 2009 Big East football scholar-athlete of the year ) who anchored the defense at middle linebacker, Williams was like a coach on the field.
• George Selvie and Jason Pierre-Paul, DE, South Florida: Say what you will about Selvie's dwindling production, but opposing offense still always had to account for him. And Pierre-Paul ascended to star status in his one year on campus. Combined, the two produced 26 tackles for loss and 10 sacks in 2009. The Bulls now need the next wave of pass-rushers to emerge, with former stud recruit Ryne Giddins one possible candidate.

Out with the old, in with the newcomers who hope to make a similar splash as their predecessors. With these five former players, it won’t be easy. Here’s a look at the ACC’s biggest shoes to fill heading into spring practices:

Clemson running back C.J. Spiller – He became the first player in college football history with 3,000 yards rushing, 2,000 yards in kickoff returns, 1,000 yards receiving and 500 in punt return yards. He left his name all over the school record books, as he established over 30 game, season and career records. He was a major reason the Tigers made their first appearance in the ACC title game.

Wake Forest quarterback Riley Skinner – He made a name for himself his freshman year by taking the Deacons to their first ACC championship since 1970 and earning ACC rookie of the year honors. Four years and three bowl games later, Skinner ended his career as the top quarterback in Wake Forest history.

Georgia Tech defensive end Derrick Morgan – His early departure to the NFL leaves a gaping hole up front. In 2009, Morgan had 18.5 tackles for loss and 12.5 sacks. His career totals include 29.5 tackles for loss, 19.5 sacks, six fumbles recovered and five pass breakups.

Georgia Tech wide receiver Demaryius Thomas – Thomas had 46 of Georgia Tech’s 78 receptions. His 1,154 receiving yards this season were the second most in Georgia Tech history, trailing only Calvin Johnson (1,202 yards in 2006). Thomas had eight of Tech’s 11 touchdown receptions and averaged a remarkable 25.1 yards per reception.

Duke quarterback Thaddeus Lewis – Lewis finished his career with 48 school records, including career total offense (9,987 yards), passing yards (10,065), pass completions (877), pass attempts (1,510), touchdown passes (67), 300-yard passing games (11) and touchdown-to-interception ratio (1.68:1). In 2009, he completed 274 of 449 attempts (61 percent) for 3,330 yards with 20 touchdowns and eight interceptions.

It's still early February, but signing day is over and you can officially start looking forward to the 2010 season. But before we look at who's back in the Big Ten, let's look at who will be missed the most when the teams return to the practice field this spring.

Here are five players who leave big shoes to fill around the league:

Penn State QB Daryll Clark: Clark finished his career as one of the best quarterbacks in Penn State history, setting team records for career passing touchdowns, single-season passing touchdowns, single-season passing yards and single-season total offense. He was even more valuable as a leader both on and off the field, and few players invested as much as the two-year starter. His presence certainly will be missed.

Northwestern QB Mike Kafka: Kafka basically became the entire NU offense in 2009 as the run game struggled. He developed into a precision passer and ended up as one of the most valuable players in the Big Ten. The second-team All-Big Ten selection led the league in both passing (3,430) and total offense (3,729). Although backup Dan Persa got some playing time after Kafka was banged up against Penn State, he'll have a tough time replacing the senior.

Michigan DE Brandon Graham: The Wolverines defense struggled mightily with Graham on the field, and it's scary to think where the unit would have been without his nation-leading 26 tackles for loss and 10.5 sacks. Graham was arguably the most disruptive defensive lineman in the country in 2009, and he leaves a major void on the edge. Michigan will need several players to step up to fill the production void left by Graham's departure.

Iowa CB Amari Spievey: Some will argue with this one, but of all the players Iowa loses from the 2009 team, Spievey could be the most valuable. He took away one side of the field, forcing opposing quarterbacks to look elsewhere and freeing up playmaking opportunities for safety Tyler Sash and others. Iowa has some decent corners coming back, but none with the shutdown capabilities of Spievey, who recorded two interceptions and 10 passes defended.

Penn State DT Jared Odrick: Penn State has little trouble reloading in the defensive front seven, but the Lions will be hard-pressed to find another Odrick in the middle of the defensive line. Odrick consistently commanded double- and triple-teams, opening up lanes for teammates to reach the backfield. Big Ten coaches named him Defensive Player of the Year and Defensive Lineman of the Year, high honors given the league's depth along the D-line. Odrick was the biggest reason why Penn State finished sixth nationally in rushing defense (89.9 ypg).

Five more who will be missed: Purdue QB Joey Elliott, Iowa LB Pat Angerer, Penn State LB Navorro Bowman, Wisconsin DE O'Brien Schofield, Ohio State S Kurt Coleman.