Kuechly was a tackling machine during his days at Boston College, a trait that transferred over to his rookie season in the NFL. As the man in the middle of a defense short on playmakers, the second-year linebacker is poised to be star at linebacker, both for the Panthers and fantasy owners.

In three of the past four seasons, Posluszny has finished as a top 20 IDP option -- and top 15 among linebackers. It all coincided with the Penn State product adding the sack to his repetoire. Without any significant upgrades to its roster of pass rushers, the opportunity remains for Posluszny to continue to make plays on both sides of the line of scrimmage.

A move to right inside linebacker seems to have done Johnson some good. He's been among the top four tacklers in the NFL in each of the past two seasons. If the Chiefs see the expected improvement in the secondary, it could open Johnson up to attack the line of scrimmage more often.

It takes a pretty special defensive lineman to crack any IDP top 10. J.J. Watt is a pretty special offensive lineman. If his league-leading 20.5 sacks weren't enough, his 16 pass deflections put him over the top. It will be tough for him to duplicate that success in 2013, but it's hard to deny he'll be the first defensive lineman off the board in most drafts.

Wagner might not talk as much as teammate Richard Sherman, but his play spoke for itself in 2012. The Utah State product did a little bit of everything while manning the middle of one of the NFL's toughest defenses. With a season under his belt, Wagner's potential is tremendous.

The leader of one of the NFL's most ferocious defenses has shown from his rookie season that he can be a do-everything player. His sack numbers were down in 2012, but it's hard to imagine he finishes a second consecutive season with less than one sack again.

Jackson is far from being a household name, but he was the top-scoring IDP option in 2011 and finished in the top 25 overall in 2012. The addition of Paul Kruger as a pass rush specialist could go a long way toward helping Jackson regain top 10 status in 2013.

Patrick Willis might be the face of the Niners defense, but in 2012, Bowman was its most productive player. Since a non-descript rookie season, the Penn State product has broken out as a defensive terror. Don't expect any of that to change in 2013.

Lee opened some eyes during his 2011 campaign and appeared to be on track to be a top 10 IDP player before an injury prematurely ended his 2012 season. Hopefully healthy this season, look for Lee to once again assert himself as one of the NFL's up-and-coming linebacker prospects.

The Patriots defense had its struggles at times during the 2012 season, but not because of Mayo. While he hasn't matched his No. 1 overall IDP finish of 2010, Mayo was a top 10 option in 2012 and should be able to duplicate that feat again in 2013.