What We Know...That junior Sheldon Day joins sophomore linebacker Jaylon Smith (reviewed here) as the unit's most indispensable player.
Day's 2013 season was beset by a nagging ankle injury and his production -- along with the Irish defensive front seven -- suffered as a result. Notre Dame needs him not only upright for the full 2014 slate, but playing at a high level in his new defensive tackle role, one that seems to suit his skill set.
"It's a good fit for Sheldon," said defensive line coach Mike Elston. "He's a little undersized at times at that spot, but when it comes to the movement traits and pass rush, he's right on track.
"Hopefully you're going to see a guy that's out there dominating. He has the ability if he stays healthy, production will be very high, be a tough guy to block. Plays with great leverage vs. the run and he's an excellent pass rusher."
-- Regarding Day's front line mates -- we know very little...
The latter pair were Cat linebackers last season, though both played often with a hand in the dirt when the Irish showed 4-3 fronts.
-- Behind the presumed starters are an injured senior, Tony Springmann (out for the spring after missing the entire 2013 season due to knee surgery), and inexperienced, unproven players -- seniors and rookies alike.
What we think we know...That Day's classmate Jarron Jones is ready for his lead role.
"As much as he still has to learn and develop from a technique standpoint, he's been productive, and you can't ignore that," said defensive coordinator Brian VanGorder.
The Irish will take that this fall when the chips are down. A productive, healthy, fully engaged Jones provides Notre Dame with a fourth reliable player up front in addition to Day, plus linebackers Jaylon Smith, and Joe Schmidt. Any more from Jones would be gravy (and welcomed) as he enters his first season of competition as a first-string player after getting a taste late last season.
-- We think Romeo Okwara, while undersized, will bring a pass-rushing presence and athleticism up front...
-- We think a healthy Tony Springmann, sophomore Isaac Rochell, seniors Ishaq Williams, Justin Utupo, Anthony Rabasa (more on Rabasa below), and Chase Hounshell (two years removed from game action after a series of shoulder surgeries), can combine forces to get the Irish through the fire…
-- We think early enrollee Andrew Trumbetti has moved to the head of a much-needed 2014 crop of front seven recruits. Trumbetti's motor is college ready even if his 250-pound frame isn't. As a spot player, the typical wear-down factor that befalls most freshmen is lessened and Trumbetti will likely carve a niche in VanGorder's scheme…
-- We think at least two, if not three more freshmen in addition to Trumbetti must contribute to the cause. True defensive linemen Jay Hayes, Daniel Cage, and Peter Mokwuah, plus edge players Jonathan Bonner, Kolin Hill, and Jhonathan Williams will each be put in position to contribute in August. They're joined by redshirt-freshman Jacob Matuska (an interior linemen). Who'll step to the fore?
Lingering questions...To be blunt, there are far more questions than answers for what has heretofore been Notre Dame's best position group of the Brian Kelly era.
Some will be answered in the season opener vs. Rice with many more pressing concerns either alleviated or coming to fruition in Game Two against Michigan.
Twelve weeks with 10 more games intermixed ensue, and Notre Dame's depth, inexperience, and strength will be tested throughout.
With between 13 and 15 bodies at Elston's disposal for the fall -- more than half of them yet to play a college down -- the fifth-year Irish defensive line coach faces the program's toughest task for 2014.
Spring Standout -- DayNo player was mentioned more by his teammates, and no player was spoken of more highly than Day, but it was senior Anthony Rabasa that enjoyed the most notable spring.
Like junior linebacker John Turner, Rabasa went from off-the-radar (at best third string) to contributor in Notre Dame's sub packages. Rabasa didn't ascend to a starter's role as did Turner, but Notre Dame's rush end position takes advantage of the Miami product's chief skill set: coming off the edge to pressure the quarterback.
"I think that's his strength. In our sub package he's a natural defensive end," said defensive coordinator Brian VanGorder of Rabasa's pass-rushing acumen. "On third down right now, that's his trait that he carries that allows him the best success."
Step Back -- Ishaq WilliamsTo be more accurate, it seems he treaded water, and Notre Dame's defense needs more from the enigmatic former five-star prospect.
Williams, along with most of the defense and its personnel, was better in 2012 than in 2013, and spring ball 2014's conversations rarely included praise for the senior defensive end.
Williams role appears to have changed from jack-of-all-trades to full-time defensive end. At 270 pounds, his toughest task will be setting the edge vs. much bigger offensive tackles.
Said Elston of the challenges Williams faces in his role: "Playing with a consistency, a grit, playing with toughness in there. Inside you're lined up on an offensive tackle, giving away 20 pounds, 30 pounds every single snap. So just having that true grit of constancy and being a tough, physical player."