Greg: Obviously it helps that Marvin Austin surprised everyone and decided to return to UNC for his senior season. But the fact that North Carolina is losing great leaders in Thomas, Wilson and Mullins cannot be understated. Add to that the sizeable crater left at nose tackle, a position manned in '09 by Thomas and Mullins, and there all of a sudden is a lot of pressure on Jordan Nix and Jared McAdoo to emerge from the shadows and compete at a high level. With All-America candidates like Austin and Robert Quinn in the rotation, the starting unit will be one of the best in the country. But UNC thrived last season in large part due to a deep rotation along the line, and that's the need that has to be met this spring.
Don: UNC rotates its defensive linemen more than any other position. Thus, whoever the replacements end up being will have plenty of experience. However, I believe the run defense will take a hit in their absence.
Buck: As Greg and Don correctly identify, it isn't necessarily the starting unit that will suffer, but UNC has enjoyed the ability to rotate their defensive tackles the last two seasons. That not only helps in terms of depth, but helps keep those big guys fresher during the course of a game and the course of a season. McAdoo is also conceivably a starter, at least in some down-and-distance scenarios. How Nix and McAdoo step up will be one key to watch this spring.
2. How much of this spring will be spent finding out about the guys behind the starters, particularly in the secondary and at linebacker?
Greg: That's the No. 1 goal for the defense this spring. Most of the starters will be entering their senior seasons and know what is expected of them, so this is the time to see who could potentially see significant action in 2011. Once training camp rolls around in August, the majority of reps will return to the starters.
Don: Every spring UNC is going to toy with its depth chart. Obviously, with the massive amount of departures in the back seven following this coming season fans and media will pay close attention to who the backups are at those positions.
Buck: I think the staff has a lot of eggs in this season's basket. While they will be somewhat forward-looking by giving extra reps to reserves this spring, with LSU as the first game I expect they will get extra attention, and perhaps they will also spend some extra time on the Georgia Tech offense.
3. Donte Paige-Moss and Kevin Reddick contributed as true freshmen last year to the defense - are there any freshmen who will arrive this fall that will make significant contributions to the 2010 defense?
Greg: The only player in the front seven that could possibly make a move would be true freshman Brandon Willis, simply because he will benefit greatly from spring practice and defensive tackle is a spot looking for valuable backups. I do think there is playing time available in the secondary behind the starters, and that's where a player like Tre Boston or D.J. Bunn could sneak into the mix.
Don: Since UNC heavily rotates its defensive linemen and John Blake has shown absolutely no fear in playing freshmen, the incoming D-linemen are the best candidates to contribute as true freshmen. Within that group, the most physically ready is Carlos Gray, while the most mentally ready is Kareem Martin.
Buck: Don is right that John Blake hasn't hesitated to get his defensive linemen on the field as true freshmen – Marvin Austin, Tydreke Powell, Robert Quinn, Quinton Coples, Michael McAdoo, and Donte Paige-Moss have all gotten on the field as true freshmen, though Austin is the only one to significantly contribute as a true freshman at defensive tackle. Tydreke got in a game early, but ultimately red-shirted because of a medical issue. Jared McAdoo red-shirted. If Brandon Willis makes enough gains in the weight room in the off-season, he may get the chance to compete next fall and Kareem Martin may get a look, but I expect Carlos Gray and really all of the defensive freshmen to red-shirt unless there are a run of injuries on the D-line.
4. As good as the 2010 defense may be, what are the weaknesses it should work on this spring?
Greg: Consistency in run defense. North Carolina allowed its final four opponents to churn out 418 yards on 132 carries (3.2 ypc). That's good, but not great. With road-grader Cam Thomas currently working out for NFL teams, the Tar Heels must plug that hole and cut down on their opponents' ability to work the clock on the ground. Pittsburgh churned out a mammoth 17-play, 79-yard game-winning drive that soaked up eight minutes and 47 seconds in the fourth quarter of the Meineke Car Care Bowl – 14 of those plays were runs. That's unacceptable if this program expects to challenge for the ACC title in '10.
Don: The run defense is going to take a hit with the graduation of Cam Thomas, E.J. Wilson, and Aleric Mullins. Someone needs to step up and be the run plugger that Thomas was. Also, Quinton Coples needs to take that next step forward and consistently make plays.
Buck: With all the returning players on defense, it would not surprise me to see UNC take a small step back in run defense next season. As Greg and Don both mention, Cam Thomas was an underrated part of last year's run defense and someone has to take on that immovable object role. Meanwhile, UNC's pass numbers might improve. Reading the combine reports, the NFL scouts haven't been giddy about E.J. Wilson's pass rushing skills. It remains to be seen, but I think UNC's pass rush will take a big step forward next year.
5. Should we anticipate any position changes on the defense this year?
Greg: Nothing of significance. Tydreke Powell may move from three-technique to nose tackle along the defensive line, but that would be about the most drastic measure taken in the starting unit. No need to mess with a good thing.
Don: If any position changes take place, it will be in the second and third string. For the most part, the starters are set.
Buck: I do think there will be some consideration of moving Powell to nose tackle, as Greg says, but the best outcome for UNC would be for Jared McAdoo step up into that role. Other than that, as Don says, any movement is likely to be among the second and third team, and I don't look for many changes there.