Last week we examined the strong points for each Top 25 team. It seems only fair that this week we consider what might derail their high hopes.
1. Alabama: Secondary
Alabama didn't lose just one or two defensive backs. It lost all four starters in the secondary, plus its top reserve. Oh, and it also has a new position coach in Karl Scott. -- Alex Scarborough
2. Clemson: Secondary
Defensive coordinator Brent Venables complained all spring about the lack of depth in the secondary, particularly at cornerback. Trayvon Mullen made strides, but there's no doubt the Tigers are going to need much more out of him, Mark Fields and A.J. Terrell this season. True freshmen Mario Goodrich and Kyler McMichael are expected to get in the mix during fall practice. -- Andrea Adelson
3. Ohio State: Linebacker
There are no glaring weaknesses on the Buckeyes' roster, but linebacker is worth monitoring entering the summer, especially after Tuf Borland's Achilles' injury suffered in spring practice. Borland (58 tackles in 2017) is Ohio State's lone returning starter at linebacker, as both Jerome Baker and Chris Worley depart. Hopes are high for young players such as sophomore Baron Browning, and if Dante Booker can stay healthy, he brings experience to the group. Although Ohio State also loses quite a bit at cornerback, it has recruited at a high level there. -- Adam Rittenberg
4. Georgia: Linebacker
It will be a bunch of fresh, unproven faces at linebacker this season in Athens. Replacing Roquan Smith in the middle of the defense is the top priority, of course, but don't forget about outside linebacker, where Lorenzo Carter and Davin Bellamy are both gone. -- Scarborough
5. Oklahoma: Safety
The Sooners should be improved at cornerback, but safety remains a huge concern. Incoming freshman Brendan Radley-Hiles, who starred in the spring, is already assured of manning either nickelback or back safety. But OU will need others to emerge to solidify a secondary that has been unreliable the past two seasons. -- Jake Trotter
6. Washington: Wide receiver
The Huskies have no clue who will be their go-to receiving threat this fall. With Dante Pettis gone, Washington finds itself pretty young at receiver, and though guys got valuable reps this spring, no one has assumed No. 1 status. Junior Aaron Fuller returns as the most accomplished receiver with just 291 yards on 26 catches last season. -- Edward Aschoff
7. Wisconsin: Secondary
Despite a historic run of producing top-10 defenses, Wisconsin has, at times, been exposed in the back end, as in its past two Big Ten championship game losses. The Badgers must replace three starters, including both cornerbacks. Safety D'Cota Dixon is back to lead the group, but Wisconsin will be relying on mostly unproven players to prevent some of the coverage busts that surfaced in the Ohio State loss last season. Defensive coordinator Jim Leonhard, a former All-America safety at Wisconsin, told ESPN.com this spring that he's confident in the athleticism of the group. But players will need to grow up in a hurry. -- Rittenberg
8. Miami: Offensive line
The Hurricanes' offensive line remains a work in progress after the spring, as coach Mark Richt has taken to repeating that mantra. But there are other areas that could use some improvement, including chemistry between the quarterbacks and receivers. Richt has placed an emphasis on trying to hit more explosive plays in the passing game. -- Adelson
9. Michigan State: Pass rush
It's hard to find an obvious concern with a team that returns 20 starters following a 10-win season. But Michigan State needs to find a second pass-rusher to complement Kenny Willekes, who led the team and tied for third in the Big Ten with seven sacks last season. The Spartans lose linebacker Chris Frey, an effective blitzer who had a team-high nine quarterback hurries to go with four sacks, and end Demetrius Cooper, who contributed 2.5 sacks and seven quarterback hurries. Senior Dillon Alexander adds some experience, and junior Justice Alexander and sophomore Jacub Panasiuk are names to watch opposite Willekes. -- Rittenberg
10. Michigan: Offensive line
The Wolverines have a few issues to solve on offense this offseason, but they won't be able to make much progress without first shoring up the line of scrimmage. New line coach Ed Warriner has some promising road-graders to work with on the interior, but the tackles are unproven and without much depth heading into 2018. -- Dan Murphy
11. West Virginia: Defensive line
To address its biggest question mark, West Virginia went out and landed two graduate transfers in Kenny Bigelow Jr. (USC) and Jabril Robinson (Clemson). The Mountaineers will be counting on both to shore up a run defense that was last in the Big 12 in 2017. -- Trotter
12. Notre Dame: Brandon Wimbush's poise
I could go with offensive line chemistry or the safety position, but if Wimbush doesn't improve in high-stress situations, it's hard to see Notre Dame contending for the playoff. Notre Dame structured much of its offseason around simulating chaos, likely with Wimbush in mind after he struggled down the stretch, completing just 44 percent of his passes with two multi-interception performances in the final four games. Wimbush took the necessary steps to improve in the winter and spring, but if it doesn't translate against Michigan on Sept. 1, Notre Dame likely will have to recalibrate its expectations. -- Rittenberg
13. Penn State: Tight end
All-conference tight end Mike Gesicki led the team in receptions (57) and touchdowns (9) last year. He and second-stringer Tom Pancoast are both gone. While the Nittany Lions' secondary also has some major gaps to fill, it looks like it will be harder to replace the game-changing offensive weapon at tight end. -- Murphy
14. Stanford: Secondary
The defense as a whole has a lot of questions to answer going forward, but the secondary really has a lot of uncertainly with the losses of top players Justin Reid and Quenton Meeks. It's hard to say how close the Cardinal have come to replacing those guys after spring practice was plagued by a rash of injuries. Alijah Holder could be one of the Pac-12's best shutdown corners, but he has suffered serious injuries in his past, making durability an issue. -- Aschoff
15. Virginia Tech: Wide receiver
The Hokies are inexperienced at linebacker, but they also have some work to do at receiver, a position that doesn't have much cover now that Cam Phillips is gone. Among the leading contenders to step up and fill the void: Hezekiah Grimsley, transfer Damon Hazelton, Eric Kumah, Phil Patterson and Sean Savoy. This is largely an unproven group, and it's one that needs to step up quickly. -- Adelson
16. Mississippi State: Wide receiver
The most underperforming group of receivers in the SEC the past two seasons hasn't improved overnight. At least not yet. Donald Gray is gone, and the hope is that the return of Malik Dear from injury and the addition of No. 1 juco prospect Stephen Guidry help pick up the slack and then some. -- Scarborough
17. USC: Quarterback
Right now, you'd have to say quarterback because neither redshirt sophomore Matt Fink nor redshirt freshman Jack Sears showed he was ready to replace early first-round pick Sam Darnold this spring. Fink has the only game experience, though very limited, and both he and Sears will be pushed by incoming freshman J.T. Daniels, who reclassified to the 2018 class. Fink and Sears ended spring more composed after struggling through the first half of practices. -- Aschoff
18. UCF: Defense
Defense is an area of transition for the Knights, not only because they have a new coordinator in Randy Shannon but also because they are going to play a new scheme that features more down linemen. UCF lost two solid starters in Jamiyus Pittman and Tony Guerad, who combined for 21 tackles for loss and 6.5 sacks. Trysten Hill returns and will be expected to have a more productive season, but this is an area where the Knights will need more players to emerge. -- Adelson
19. Auburn: Wide receiver
Jarrett Stidham was in need of playmakers at receiver before Eli Stove and Will Hastings both suffered serious injuries this spring. Now the outlook will be even more ominous if someone such as Nate Craig-Myers doesn't step up. -- Scarborough
20. TCU: Offensive line
The Horned Frogs graduated four starters off last season's offensive line, leaving that as the major question going into the season. It would help if Anthony McKinney, the No. 1 incoming junior college tackle in the country, could nail down one of the bookend spots. -- Trotter
21. Boise State: Wide receiver
The Broncos graduated All-Mountain West wideout Cedrick Wilson, who accounted for 83 receptions and a school-record 1,515 receiving yards. No returning Boise State pass-catcher had more than 33 catches or 500 yards last season. Brett Rypien might be the top returning quarterback in the Mountain West. But to be effective, he'll need young targets, such as Octavius Evans, to emerge. -- Trotter
22. Texas: Running back
Running back was a disaster for the Longhorns last season, as quarterback Sam Ehlinger amazingly led Texas in rushing with 381 yards, despite starting only six games. The Longhorns are banking that a pair of intriguing additions in Cal graduate transfer Tre Watson and ESPN 300 signee Keaontay Ingram will bolster the position. -- Trotter
23. Texas A&M: Wide receiver
It's a good thing Trayveon Williams is back and Jimbo Fisher likes running the football because there aren't many difference-makers at receiver to turn to now that Christian Kirk has moved on to the NFL. Jhamon Ausbon and Kendrick Rogers could develop into solid starters, but they'll need time. -- Scarborough
24. Oregon: Cornerback
The Ducks have questions about depth and experience at cornerback this season. Only sophomores Thomas Graham, who was a regular starter for the Ducks last season, and Deommodore Lenoir have seen game action in this group. Graham is the leader of the group, while Lenior dealt with inconsistencies his freshman year. Oregon's corners had a very up-and-down spring and even had to use multiple walk-ons to help with numbers. -- Aschoff
25. South Carolina: Tight end
When All-SEC tight end Hayden Hurst walked out the door for the NFL, South Carolina didn't have a clear option or two to replace him. Only Jacob August, K.C. Crosby and Kiel Pollard had catches last season, and even then they combined for just nine. -- Scarborough