Nebraska returns senior quarterback Taylor Martinez and most of the firepower from the Big Ten's top offense in 2012. Most believe the Huskers' season hinges on a young, inconsistent defense under the guidance of coordinator John Papuchis and head coach Bo Pelini.

The Blackshirts finished fourth nationally in pass defense and ninth in pass efficiency defense in 2012, but they struggled against the run (90th nationally) and hemorrhaged points in Nebraska's four losses, surrendering 63 to Ohio State, 70 to Wisconsin in the Big Ten title game and 45 to Georgia in the Capital One Bowl. Nebraska must replace all three starting linebackers and its top pass-rusher, Eric Martin, among others. The Huskers return an experienced secondary led by nickelback Ciante Evans.

ESPN.com caught up with Papuchis earlier this month to discuss the state of the Nebraska defense.

After looking at the unit during spring practices, what were some of your big takeaways from their performance?

John Papuchis: That's an interesting question because what I've been doing the last couple weeks is going back and looking at our spring cutups. One thing that jumped out to me, after having a little bit of time away from it, was that we improved pretty significantly and steadily as the spring went on. From the first practice to the 14th practice leading up to the spring game, we were much crisper in our alignments and understanding our assignments, we played faster. There was just a lot of development that took place over the course of those 14 practices. We're a young group, and we're going to need all 29 practices before we kick it off against Wyoming.

Were there specific areas or groups where you saw the most improvement, or was it across the board?

JP: Each position group has its own learning curve. Defensive line, we are relatively young, so for a lot of those guys, it was their first opportunity to really get coached. Where I saw the improvement had more to do with technique than it ever had to do with scheme. They had a pretty good feel of the scheme; it's a little bit simpler in terms of what they're asked to execute. Linebacker, another young group, and where I really saw their improvement was just better understanding of alignment and where they fit in the run game and the pass game. And then in the secondary, where we are a little bit more mature, Ciante Evans, Stanley Baptiste, Mo Seisay, Harvey Jackson, Corey Cooper, where I really saw those guys make a jump is just a better feel of the nuances of the defense. They were kind of a little bit ahead, the linebackers and D-line, and they showed improvement as spring went on, but it was kind of Level 2 and Level 3 improvement, as opposed to just the basics.

Who do you look for to be leaders up front and with the linebackers, and how much competition do you anticipate with those groups?

JP: There's going to be a ton of competition, and that's going to be a good thing for us. Really since I've been here, the way things have fallen, a lot of times going into camp, you have a pretty good idea of who your core guys are going to be. And although we have an idea right now, there are some spots that need to be ironed out. In terms of leadership, Jason Ankrah and Thad Randle across the front. Both of those guys are fifth-year seniors and have been in the program a long time. Jason has started and played a lot of games for us. Thad has been a little nicked up the last two years. But both of them have done a nice job of being leaders through the offseason.

Linebacker, we're young, but the one guy who has some pretty good playing experience is David Santos. He's done a good job of taking that leadership role. And another guy who has been in the program for a while and has played on special teams, and has always been one play away from having a more significant role is Trevor Roach. He's done a nice job of being a leader and more of a veteran guy with that group.

You mentioned for some of the young players, this has been their first chance to really get coached. Who really stood out to you among that group?

JP: I was really pleased with both of our young defensive ends, Avery Moss and Greg McMullen. Both of those guys had really good springs, and they got better as the spring went on. They made pretty dramatic leaps from Day 1 to the end of it. I was pleased with that. Inside, Vincent Valentine, Aaron Curry, Kevin Williams, they all had pretty solid springs. Brodrick Nickens, he's a guy who we moved over from the offensive line, a really talented athlete but just hadn't been able to find his home on offense. He's a big body who really did some good things for us on the D-line. There's a bunch of guys who were learning for the first time, but that's going to create some competition and some enthusiasm going into fall camp.

Same thing at linebacker with the young players. Did any of them really stand out to you?

JP: I think Jared Afalava was the guy who impressed me. He seemed like he had some very natural instincts at that position, just a good feel for the spot, things you don't necessarily teach. David Santos got better, played some (middle linebacker) for us, a different role for him but thought he did a nice job. And Zaire Anderson. For Zaire, who's a really talented kid, it was his first real opportunity to take in everything that we're doing defensively. Even though he came last fall, he got hurt after three weeks and fall camp was really a whirlwind. This spring was critical for him, and he's going to be a big piece going forward.

You're adding Randy Gregory to the mix from the juco ranks. Where do you see him fitting in?

JP: He's certainly going to factor in. Whether it's in a pass situation role or an every-down role, it's a little early to say. The thing about Randy is obviously he hasn't been here yet. But I think he's going to help us, he's going to be important to what we do, but I want to try to temper some of the expectations on Randy because although we feel like we have a good understanding of who he is and what he's going to be able to contribute, without him being here, he's a little bit of an unknown quantity at this point.

I wanted to ask about Ciante. Where do you see his role going this year? Will it change or expand at all?

JP: I thought he had a great year a year ago. His role is critical for us. We put a lot on that nickel position. A lot of times, he's covering the opponent's top guy because that guy's in the slot position. He asked to be in our pressure package, he's asked to be in our run fits, and obviously he's asked to cover, so the guy who plays that spot has to be pretty versatile, and he is. And just like everybody else that has these three or four years to mature, he's grown into a leader for us. He's been in some big games and in some big spots, from his true freshman year to this point now. You can see that he's matured, and I think he's poised to have a good senior year.

There are so many other guys with experience back there. How much competition do you see at both the safety and corner spots in camp?

JP: I think the corner battle is going to be really interesting because there's a bunch of guys that can win spots. Stanley Baptiste, Andrew Green, Mo Seisay, Jonathan Rose, a bunch of guys can all compete for playing time. Ultimately, who comes out as the No. 1 guy on that other side of nickel, we'll see in camp. When we're not in nickel, Ciante is going to play one of those corner spots, so you're looking at four pretty talented guys competing for really one spot opposite Ciante in base.

Can you be a defense led by the secondary? A lot of coaches like the leadership up front or at linebacker, but experience-wise, you have so much more in the back four.

JP: Well, there's been times that we've had that in the past, and it's worked for us. The year we had Eric Hagg and Prince Amukamara and DeJon Gomes, that was a pretty secondary-led group. When I was with Bo at LSU, our strength was in the secondary. So this isn't the first time we've had that. And what sometimes gets lost in translation for a variety of reasons is I thought in the back end, we had a pretty good season a year ago. For most of the year, we led the country in pass defense. I think we ended up leading the country in opponent completion percentage (47.1). So our guys had a good year in the back end. Part of that is the way we structure our scheme, and part of that is they had a heck of a year.

So does that really put the focus in camp on the front seven?

JP: Obviously, that's where we have the most question marks, so fall camp is going to be incredibly important for those guys. The thing I like is I think we have more depth than we've had. I can't say for sure who I think are going to be the guys who line up against Wyoming, but I do think we have six or seven guys that compete at end, six or seven guys that compete at D-tackle. The first few opponents we play are going to be more spread offenses, so we're going to be in more nickel, and we're going to have two backers on the field as opposed to three. Between David Santos, Jared Afalava, Zaire Anderson, Trevor Roach, Josh Banderas, who's a freshman, Courtney Love, a freshman, I think we'll be able to have some depth at that spot as well.

Bo is always involved with the defense. When it's a younger group, do you expect him to be even more involved?

JP: I imagine it's going to be business as usual. Obviously his background and one of his great strengths as a coach is defense, so I don't ever really see a scenario where he's hands off in terms of what we're doing on defense. But I don't know this year will be any different than any other year.

Did you guys visit any other teams this offseason?

JP: We did. There's going to be some new wrinkles. I would like to keep what we looked at and who we visited a little bit under wraps, but we're going to be able to have some new wrinkles, and some of the athleticism that we'll have on the field is going to allow us to have a little bit more versatility.

Where would you like to be as a defense coming out of fall camp?

JP: Number one, I want our guys to have a firm grasp of what we're asking them to do. Because we are so game-plan specific, I'm not as concerned that every guy on our defense knows every part of the playbook. We cater what we do specifically to who we're playing that week. However, they do need to understand the general concepts. Number two is to really have a solid feel of who our working two-deep is. I want to know coming out of camp who our guys are, and I want to see them fighting for those spots. To really have defined goals is hard to say in camp because we're going against our offense every day, but I want to see us get a little bit better.

The way our schedule sets up is interesting and a little bit unique in that we have two open weeks in the first six. So the way I look at it, we need to keep getting a little bit better every week. With a young group, you have that opportunity. We need all four weeks of fall camp, we need our four nonconference games, we need our two early conference games and we need our two bye weeks. It's about a three-month period where we need to continue to improve over the course of all three of those months going into November, where we play five games where, let's face it, those are going to define our season in a lot of ways.