It is common knowledge among Notre Dame fans that Irish defenses of the last 10 years have been mediocre at best.
Defense was never a true priority to Charlie Weis, so the recruiting of defensive players suffered.
However, Weis was able to bring in 5-star linebacker Manti Te'o, the biggest defensive recruit to sign with Notre Dame since the Lou Holtz era.
Brian Kelly has certainly made building a strong defense priority number one.
He got off to a great start to that project by signing three of the nation's top defensive recruits in the 2011 cycle.
The signing of those players was surely aided by the strong play of the defense in the last four games of 2010 in which the defense yielded only 40 points.
Nine of the 11 starters from that defense return this season in what should be a BCS bowl season for the Irish.
Follow along as we count down the five most important players on Bob Diaco's defense.
With the Irish secondary being a paper-thin unit, the play of cornerbacks Gary Gray and Robert Blanton will be crucial to the success of the pass defense.
Experience may be the greatest asset of these two players as both are in their final years of eligibility.
Similar to the situation at running back, Gray and Blanton must avoid injury or else the secondary will take a huge blow.
A healthy Gray and a healthy Blanton will add up to a solid pass D this season.
Many of you may disagree with Nix being on this list, but he will be a critical part of the Irish D-line this season.
His ability to stuff the run on his own is thoroughly impressive.
Nix's endurance is certainly something that has to be questioned, though.
If strength and conditioning coach Paul Longo can work on increasing his endurance, then Nix will see the field more often.
However, Nix has the potential to be the anchor of the D-line in seasons to come.
Lynch is regarded as the gem of the 2011 recruiting class.
A 6'5", 250-pound bruiser, Lynch will provide speed and tenacity coming off the edge at the defensive end position.
That is something that Notre Dame defenses of the past 10 years have altogether lacked.
Lynch will need to be on the field for the Irish to shut down the run and get in the face of opposing quarterbacks.
While he is inexperienced, his raw athleticism and talent will make up for any mistakes he'll make.
Rated as one of the best safeties in the nation heading into the season, Harrison Smith figures to be crucial element in Bob Diaco's 3-4 scheme.
Smith came on strong at the end of last season, picking off the game-winning interception at USC and grabbing three more in the Sun Bowl against Miami.
He will also provide leadership as he is in his fifth and final year in South Bend.
Look for Harrison Smith to continue to be a game-changing player in the secondary this season.
Perhaps the best defensive player to have ever donned the Blue and Gold, Manti Te'o is far away the most important player on the Irish defense.
His speed and knowledge of the defense make him the most effective player on the field.
Not only is he the best player, but he is also the heart and soul of the Irish D.
It is expected for Te'o to be a first-team All-American at season's end.