Notre Dame Football: Who Will Be the X-Factor on Irish's 2013 Defense?

Notre Dame finished seventh in the country last year on the defensive side of the ball, and it will need a similar effort if the success if going to carry over to the upcoming season. The possibility of this happening is fairly good with eight starters returning and a few guys coming back from injuries.

But even with starters solidifying their spot with the first-team and a bunch of familiar faces remaining in the lineup, it is often the guys under the radar that emerge and make the biggest difference. You can call this player the X-factor of the defense.

Last season it was freshman KeiVarae Russell stepping up in the secondary, now it will be Ishaq Williams at the linebacker spot.

Williams still has his work cut out for him if he is going to be a starter in the 2013 season. With Prince Shembo still hanging around, the battle for the CAT linebacker position remains up for grabs. However, regardless of who walks away from offseason drills with the starting spot, you better believe Williams will receive more playing time than he has in the past.

Playing in 13 games as a backup last season, he finished the year with 22 tackles and 3.5 tackles for loss. In a limited role, he made big plays throughout the season for the Irish in some of the biggest and hairiest situations.

Now it is time for him to receive more playing time and become that difference maker to help keep this defense at the top of college football.

Williams fits the CAT linebacker position in this Bob Diaco defense perfectly. To play this position you need to be able to operate in space, be an excellent pass-rusher and have the ability to shed blocks in order to make plays in the backfield. That is what Williams is, an athletic player who uses his speed and great hands to become a disruptive defender.

Coming out of high school mainly as a defensive end, many scouts thought he would remain in that position due to him being a liability in pass coverage. While this may still be an issue with Williams, the CAT position isn't asked to drop back into coverage nearly as much as the DOG linebacker is, somewhat limiting his weaknesses.

Notre Dame has a defensive line that should remain one of the best in the country with Stephon Tuitt, Louis Nix III and Sheldon Day providing a scary front. Now the team needs that extra pass rusher to come off the edge and continue to make this defensive line the strength of the defense. This is what Williams was known for when he first arrived in South Bend and that hasn't changed.

Head coach Brian Kelly told Tim O'Malley of Scout that while Williams hasn't locked up a starting position, the strength of the defense will likely come from the CAT linebacker.

"

He’s still in a competitive situation in terms of playing time. We think the combination of those two guys (Shembo) gives us the best chance at that position. And so what I think you’ll see, across the board with this team, is the sum of this team is going to be greater than any one of its parts. If you stand back and look at it, that’s this kind of football team that’s coming together — a lot of guys playing, a lot of guys contributing. And the strength of us will be Ishaq and Shembo playing that position.

"

Whether Williams is starting at linebacker, playing a more significant backup role, or somehow thrown into the mix at defensive end, this is somebody with excellent pass rushing skills and will be valuable to another Notre Dame BCS run in 2013.

Some would say that Manti Te'o was the reason this defense was so great a year ago, but it truly all started with the defensive line and a pass rush that produced 33 sacks and 45 quarterback hurries. Williams will have his hand in that success next year and it will be key in preventing this unit from taking a step in the wrong direction.

Follow @Randy_Chambers