Our series looking at the top positions battles concludes with an area that will feature plenty of new faces in the middle of the Irish defense.
No Manti Te'o in 2013 was a bigger adjustment than most expected. The veteran presence of Dan Fox and Carlo Calabrese kept things familiar, with Fox moving to the Mike, losing his job to Jarrett Grace, then bouncing back to play some of the best football of his career to close the 2013 season.
Now both are gone, and while the Irish lose Prince Shembo at the starting Cat linebacker spot as well, it is presumed that Ishaq Williams will step in with the chance to fill those shoes. (Jaylon Smith was a freshman sensation as the starting Dog linebacker.)
Grace figured to be the starting Mike, but his recovery from a broken leg means that the doors are open this spring for others to step up and make their marks. Kendall Moore is back for a fifth season and figures to play a big role this spring. So does redshirt junior Joe Schmidt, the former walk-on who earned a scholarship entering last season and played significant action inside in 2013.
One other thing to consider is that there is a new defensive coordinator in Brian VanGorder. And although Brian Kelly said that the Irish will still operate out of a 3-4 base and go 4-3 about half the time, it remains to be seen how much more aggressive, if at all, VanGorder is with the personnel at hand.
There will probably be plenty of mixing and matching this spring, as the Irish try to find where some of their young guys are most effective -- notably, Michael Deeb and Doug Randolph, a pair of players who redshirted last season as freshmen.
Outside linebacker has a bit more depth, with Romeo Okwara and Ben Councell, who will likely miss the spring after tearing an ACL late last season. And a major reinforcement inside could be on the way this summer in Nyles Morgan, the No. 5 inside linebacker in the nation and Notre Dame's top recruit from the 2014 class.
But that's a topic for fall practice. In the spring, the Irish need to work on replenishing the position unit that takes the biggest hit from 2013 to 2014 in linebacker, and in particular, at inside linebacker. Several players have opportunities to cement significant roles for the 2014 season.