Spring preview: Defensive line

With spring practice beginning on Saturday, HuskerOnline.com continues our in-depth look at each position with our 2014 spring position previews.

Today, we analyze and breakdown the defensive line heading into the start of spring practice.

What we know right now: Nebraska has some definite star power on the front four in defensive end Randy Gregory, who took the Big Ten Conference by storm last season by emerging as one of the league's best pass rushers off the edge. Gregory will come into the season with plenty of hype, and he certainly won't be taking anyone by surprise this time around. Inside, the Huskers boast some solid returning experience at defensive tackle that could make a big jump from the young unit that had to learn on the fly in 2013. Vincent Valentine, Aaron Curry, Maliek Collins, Kevin Maurice and Kevin Williams will all be battling for playing time at defensive tackle this spring and on into fall camp.

However, Nebraska will be missing one of its key pieces from a year ago in defensive end Avery Moss, who was suspended from the team for an off-the-field incident and will miss the entire 2014 season. His absence leaves the Huskers with just four scholarship defensive ends this spring, meaning the group will be getting a lot of reps over the course of the next few weeks. Also, it will be interesting to see how much work Williams gets during spring ball, as he's coming off his second major knee injury that sidelined him most of last season.

Biggest question to answer: Without a doubt the biggest question facing Nebraska's defensive front is who is going to step up and fill Moss's shoes at the starting defensive end spot opposite Gregory. The most likely candidates are Greg McMullen, A.J. Natter and junior college transfer Joe Keels, who will participate in spring ball. McMullen is the only player to see live game experience so far, but that by no means makes him a lock to take Moss's place once the season rolls around. Natter impressed both his teammates and coaches with his play on scout team while redshirting last season, and Keels is expected to immediately join the rotation in some capacity, especially with NU's lack of depth at the position.

Spring dark horse: Assuming his development stays on the same trajectory it was on throughout last season, Natter could end up being a mainstay for Nebraska at defensive end this year, if not potentially even winning a starting spot. Listed at 6-5, 240, the Milton, Wisc., native still needs to add some bulk to his frame, but his work ethic and toughness make him a perfect fit for what the Huskers are looking for at the position. Natter is a guy who just looks the part of a Big Ten defensive end, and given the opportunity ahead of him to see the field a lot this season, he could become a major factor for NU up front.