Most important fall camp storyline for each Top 25 team

How does Oklahoma replace Mayfield? (1:18)

Rece Davis explains how Kyler Murray will have to replace Baker Mayfield as starting QB, while Murray has a future baseball career on the horizon. (1:18)

What's the biggest issue in fall camp for each of the nation's top teams? There are QB battles, new faces trying to step up and one high-profile coach controversy among our preseason Top 25 Power Rankings.

1. Alabama: Rebuilding the secondary

Let's set aside the QBs and focus instead on a secondary that lost every major contributor it had last season. Think about it: That's not just all four starters but the two top reserves as well. True freshmen Patrick Surtain Jr. and Josh Jobe look like they might be able to step in and make an impact, but coaches have a handful of newcomers they have to get ahead of the learning curve to shore up the back end of the defense. -- Alex Scarborough

2. Clemson: Looking for a TE

Yes, we know the quarterback battle is the biggest talking point for Clemson during fall camp, but that's a no-lose situation. The Tigers either end up with a guy who led them to the playoff or they've found someone better. If you're curious about a real need for Clemson, watch the tight end spot, a position that was critical during the Deshaun Watson era but lacked real punch last season. Milan Richard returns as the most experienced of the bunch, with Garrett Williams close behind and a wild card in freshman Braden Galloway. -- David M. Hale

3. Ohio State: Meyer's future

The past week changed everything. No longer is the focus on Dwayne Haskins' anticipated development into a star QB or the load handled by standout running back J.K. Dobbins. It's all about Urban Meyer and, ultimately, who coaches the Buckeyes this fall. The newly appointed independent working group will likely provide key hints soon. -- Mitch Sherman

4. Georgia: How best to use Justin Fields

It's not a question of if Fields will unseat Jake Fromm as starting quarterback. That's not anywhere close to happening. But it's fair to wonder how the Bulldogs will use Fields, the dynamic freshman and former No. 1 overall recruit. Coach Kirby Smart said Fields won't redshirt, so it will be interesting to see how Smart and offensive coordinator Jim Chaney devise ways for Fields to get on the field as a changeup to Fromm. -- Scarborough

5. Washington: Finding reliable wide receivers

When Jake Browning had both John Ross and Dante Pettis to throw to two years ago, he put up some of the best passing numbers in the country. Last year, without Ross, those numbers took a sharp dive, and now, without Pettis, the Huskies are light on proven options for Browning to throw to. Who steps up to fill that void? -- Kyle Bonagura

6. Wisconsin: Finding replacements at cornerback

How do the Badgers fill big holes at cornerback? Sophomore Dontye Carriere-Williams handled important reps, but the heavy lifting last season went to Nick Nelson and Derrick Tindal, both departed. This program doesn't plug gaps in the secondary like it manufactures linemen. The rock-solid pass defense of 2017 might be tough to replicate. -- Sherman

7. Oklahoma: Safety concerns

The Sooners are hoping to improve defensively, but that will hinge heavily on what happens at safety. With little experience returning at either safety spot, Oklahoma has already bumped cornerback Jordan Parker there. The Sooners are hoping they can keep highly touted freshman and preseason Big 12 Newcomer of the Year Brendan Radley-Hiles at nickelback. But if the back end falters early on, Oklahoma will be forced to reshuffle the versatile Radley-Hiles there. -- Jake Trotter

8. Penn State: Are the true freshmen ready?

The defense lost two defensive line starters, two linebacker starters and essentially the entire secondary from last season. The offense lost its leading receiver in DaeSean Hamilton, leading rusher and second-leading receiver in Saquon Barkley and third-leading receiver in tight end Mike Gesicki. Penn State will need a lot of help this season from its young players. Luckily for the Nittany Lions, there are some potential playmakers in the 2018 recruiting class. Linebacker Micah Parsons was a five-star who is expected to contribute right away, wide receiver Justin Shorter is much of the same on the offensive side, and running back Ricky Slade should pair well with junior Miles Sanders in the backfield. -- Tom VanHaaren

9. Miami: Offensive line issues

The Hurricanes struggled along the offensive line during spring practice, so getting that position shored up in the fall is a priority. One player to watch is Navaughn Donaldson, who started 10 games as a true freshman at right guard last season but has moved over to right tackle to ease concerns at that position. Donaldson has lost 10 pounds and is in much better shape, but he's still getting adjusted to playing tackle. -- Andrea Adelson

10. Auburn: Help at wide receiver

We all know by now how talented a quarterback Jarrett Stidham is. But to whom will he throw the football? Two of his top receivers, Eli Stove and Will Hastings, are recovering from serious knee injuries. And, frankly, there hasn't been a go-to guy at the position in a while. Maybe Nate Craig-Myers will finally emerge. Maybe Ryan Davis will take another step forward. Either way, Stidham will need help. -- Scarborough

11. Notre Dame: Picking a QB

Which quarterback gives the Irish their best chance to challenge for the College Football Playoff? Brandon Wimbush figures to start the opener against Michigan, with Ian Book ready as a backup. But freshman Phil Jurkovec is going to play, too. And if the guys ahead of him slip, the freshman might just help take Notre Dame to a higher level offensively. -- Sherman

12. Michigan: Improving the passing game

Michigan cycled through three quarterbacks and saw plenty of struggles along the offensive line in 2017. The Wolverines finished 2017 ranked 110th in pass yards per game, 113th in net yards per pass attempt and 117th in sacks per pass attempt. It has been a busy offseason of trying to remedy those numbers for Jim Harbaugh, mutually parting ways with offensive coordinator Tim Drevno, adding offensive line coach Ed Warinner and tight ends coach Sherrone Moore, and landing quarterback transfer Shea Patterson from Ole Miss. The depth at quarterback with Patterson, who is eligible immediately, Brandon Peters, Dylan McCaffrey and true freshman Joe Milton, along with a more veteran offensive line, should equate to better results. Fall camp will help the coaching staff figure out if they're on the right track or if they're in for another long season. -- VanHaaren

13. Michigan State: Is LJ Scott the guy at running back?

Quarterback Brian Lewerke appears set for an outstanding season. He returns his top three leading receivers in Felton Davis III, Darrell Stewart Jr. and Cody White and will have a more experienced offensive line. The question that remains is how Scott will perform. He ran for 898 yards but had issues with fumbles and blocking last season. He was the leading rusher last season in terms of yards and is going to be relied on heavily this season, as Madre London and Gerald Holmes, last season's second- and third-leading rushers, are no longer on the roster. If Scott can hold on to the ball and be a reliable back, the offense could take a big step forward. -- VanHaaren

14. Stanford: Finding stability at QB

The Cardinal have been without stability at quarterback since Kevin Hogan's career ended, switching starters midway through each of the past two seasons. In redshirt sophomore K.J. Costello, Stanford should finally be set, but it still remains to be seen if Costello can take that next step and take advantage of the extra attention that running back Bryce Love will surely draw from opposing defenses. -- Bonagura

15. Virginia Tech: Developing the secondary

There are plenty of questions looming over Virginia Tech's fall camp, but none larger than the need for rapid development in the secondary. Bud Foster's defense is designed around putting his corners on an island and playing aggressive with blitz packages, but that gets tougher after the Hokies lost three DBs to the NFL, another to academic issues and another to injury this offseason. There's some talent remaining, with Divine Deablo, Bryce Watts and Caleb Farley, among others, but experience is thin, and some key players will need to grow up fast. -- Hale

16. USC: Who will start at QB?

Until coach Clay Helton makes a decision, the Trojans' quarterback competition will be front and center. It's the uncertainty at that position that has tempered expectations for a team that has a well-constructed roster and is coming off a Pac-12 championship. Helton said he'll make the call among true freshman J.T. Daniels, redshirt sophomore Matt Fink and redshirt freshman Jack Sears after about 20-25 practices. -- Bonagura

17. Mississippi State: Offensive help

Joe Moorhead's reputation as an offensive mastermind precedes him, but it remains to be seen what magic he will work in Starkville. While quarterback Nick Fitzgerald and running back Aeris Williams have already established themselves as playmakers in the SEC, there need to be more threats on the outside. Keith Mixon could be an option there, along with juco transfer Stephen Guidry. -- Scarborough

18. Florida State: Settling the QB competition

Once again, all eyes are on the quarterback competition, with one key difference. Deondre Francois is completely healthy following a knee injury that cost him nearly all of 2017. He, James Blackman and Bailey Hockman will split the reps evenly as they go through practice, and coach Willie Taggart hopes to have a starter in place before the season opener against Virginia Tech on Sept. 3. -- Adelson

19. Boise State: Transition at receiver

The only real question mark for a veteran-laden team is receiver and the production vacated by 1,500-yard wideout Cedrick Wilson, a senior last season. The Broncos are hoping that promising sophomore Octavius Evans can help make up for that loss. He has already been turning heads this preseason. -- Trotter

20. West Virginia: Holding the line

The Mountaineers have a Big 12 championship-caliber offense. They have playmakers such as David Long, Dravon Askew-Henry and Kenny Robinson in the back eight defensively. But can the Mountaineers hold up on the defensive line against the Big 12's best? West Virginia has given up more than 300 rushing yards to Oklahoma in four of the past five years, all in losses. The Mountaineers are banking on graduate transfers Jabril Robinson (Clemson) and Kenny Bigelow Jr. (USC) elevating the defensive physicality in the trenches. -- Trotter

21. TCU: Rebuilding the offensive line

The Horned Frogs lost five seniors on their offensive line, four of whom are in NFL camps, and return just two: guard Cordel Iwuagwu and tackle Lucas Niang, who both have starting experience. How quickly TCU grows up on its offensive front is key. -- Sam Khan Jr.

22. Texas: Getting better OL play

How much improvement will the offensive line make? It was a source of depth issues and inconsistency last season and one of the key reasons the Longhorns struggled to run the ball consistently. With some new recruits and a graduate transfer (former Rice tackle Calvin Anderson) on board plus a new offensive line coach (Herb Hand), the Horns are optimistic about their prospects, but there's no doubt that they have to get better on the O-line this season. -- Khan

23. Oregon: Adjusting to new offense

Externally, as is usually the case when there's a change at head coach, there will be plenty of questions about how the offense will look with Willie Taggart off to Florida State. Wholesale change isn't expected -- Mario Cristobal was the offensive coordinator a year ago -- but there will be noticeable differences. One change to expect: The Ducks will line up regularly in the pistol formation. -- Bonagura

24. UCF: Transfer receiver's impact

Now that Ole Miss transfer receiver Tre Nixon is eligible to play for UCF this season, the question is how much can he contribute to this up-tempo offense? UCF lost its leading receiver, Trequan Smith (1,171 yards), and though the Knights return talent and depth at the position, Nixon's speed, competitiveness and maturity could give him an opportunity for a breakout season. -- Adelson

25. South Carolina: Adjusting to up-tempo offense

Will a faster tempo mean more offensive production for the Gamecocks? With Bryan McClendon now in the offensive coordinator chair, South Carolina is aiming to go up-tempo offensively to help Jake Bentley & Co. get more productive. Bentley looked sharp and comfortable in the spring game. If the Gamecocks continue to improve and grasp the offense, it should pay dividends during the season. -- Khan