Without them, there's no 2012 Maxwell, Bednarik, Lombardi, or Walter Camp Trophy to be displayed in the now crowded front hall of the Guglielmino Athletics Complex.
Without them, there's no Frank Broyles Award mention, no FWAA or Home Depot Coach of the Year honors to collect.
And without them, 12 wins without defeat would have been a pipe dream rather than dream scenario turned reality-TV for long-suffering Irish fans.
Notre Dame could have still produced a strong football team this year with just a little less from its defensive linemen, but there's little doubt it was that group's collective effort that allowed the three weeks since Thanksgiving in Los Angeles, and the next three to come, into a national celebration of all things Notre Dame football.
"I really wouldn't pick just one," said the unit's coach, Mike Elston when asked to distinguish a D-Line leader. "I love all four of those guys that play across the front."
So does the team leader that plays directly behind them.
"I have monsters in front of me," said Manti Te'o of Louis Nix, Stephon Tuitt, Kapron Lewis-Moore, Prince Shembo, and their quartet of capable backups.
The national headliner of the group is All-America defensive end Stephon Tuitt. But more important than Tuitt's year-end accolades and telling of the unit as a whole is this: Tuitt might have been the position group's third-best player in October and November.
"This is really, truly his first full year of playing the game," said Kelly of the Monroe, Ga., native. "And he went through some ups and downs. You know, playing in a 12-game schedule was a little different. There were some areas where we had to get him through week eight or nine or ten. So we saw a guy really maturing and developing, but more than anything else, accepting the role on defense is what we, as coaches, most appreciate."
That role was to stop the run and, in most instances, take on two offensive linemen in a gap-control scheme. And oh-by-the-way, the second-best sack total in program history manifested along the way.
"Stephon's process in terms developing into the player that he is today has been one where he had to be unselfish first and foremost," said Kelly. "He had to be a guy that was committed to being solid against the run and not just, I want to be an edge player. He's seen, by the number sacks that he has this year, that he can be both.
"So the transformation for Stephon Tuitt for us is that he's embraced his role of being a guy that will play the four technique and be a two-gapper against the run, and also be able to rush the passer."
As Tuitt's chief tutor, Elston offered his pupil's evolution from freshman contributor to sophomore star wasn't a shock to those in charge of his development.
"I had hoped that he'd improve. You spend every day preparing practice for a young man to improve his game. I just want to move these guys (the defensive linemen's) games forward and make them better players, and as the season goes on, give them things to work on and that's what we did and Stephon had a very good season.
"I was not shocked Stephon moved his game forward and made the improvements that he needed to make to be successful," he continued. "I'm excited that he did and he's going to be hopefully improving between the USC and Alabama game."
Big Man on Campus
College football produces dozens of underrated, hidden talents each season. Somehow, the nation's most storied program -- in the midst of a 12-0 season, no less -- boasts that categories top dog for 2012, dominant junior nose guard Louis Nix.
"The reason you get into college coaching is to see the development of the full player, the full student, the full man that you're working with and to see it with Louis, its exciting," said Elston of Nix's three-year development, all under the current coaching regime.
Admittedly disappointed by post-season snubs on the awards circuit and from All-America teams, Nix worked through those frustrations by looking ahead, both in the classroom and on the field vs. the Crimson Tide next month.
"I feel like I have a lot to prove still, on and off the field," said Nix of his recent decision to return to school for his senior season in lieu of an NFL paycheck. "I have to finish my film and TV degree and my business minor. I should be graduating by the end of the fall next year."
"I'm looking forward to my one-on-one matchups, if I get an opportunity to have one, I think I will," said Nix of the forthcoming title tilt. "I guess they're physical enough to block one-on-one. I want to take on that challenge and hopefully they'll (have to) double-team me. That's the type of stuff people want to see. I (generally) attract two or three guys, so we'll see how that goes."
A combined 19 tackles for loss, with 13.5 sacks, 21 official quarterback hurries, more than 85 total tackles and four turnovers created.
Three months of consistent production by Notre Dame's defensive end tandem of Kapron Lewis-Moore and Prince Shembo served as one of the season's pleasant surprises. Lewis-Moore was previously solid; Shembo showed potential, though more so as a true freshman than last year as a fish-out-of-water Dog linebacker.
"Its incredible. I had a meeting with him the other day and talked to him about (his continuous improvement)," said Elston of the 5th-year senior and co-captain Lewis-Moore. "I'm proud of Kapron for the progress he's made and he's continuing to make progress. Just the other day in practice, there are things that he works on and he's really set himself up for a great future. He's done a fantastic job on our D-Line and he's been a great leader and his play has spoken for itself on the field."
Lewis-Moore tops out around 305 pounds. Tuitt at 300, and Nix -- officially at 326, or as he joked during this week's media day, "Around 300 I guess." The only undersized front-liner is the hybrid OLB/DE Shembo, a natural pass rusher who dutifully served in space and in coverage far too often last fall.
"It was definitely to get our best players on the field at the time," said Kelly of Shembo's season at the Dog 'backer position. "Prince obviously plays much better when we can shorten the field and he can get after the quarterback. He's great over at tight end. It's just a more natural fit for him being at the Cat position."
It's more natural because the position allows Shembo to play with his hand down as a 4-3 defensive end in well over 50 percent of a game's defensive snaps.
"You've got a guy that (is) so strong against the runs, and then give you great effort, too. He's a guy that doesn't take a play off," said Kelly.
Charge of the Backup Brigade
Shembo and his starting cohorts have no need to take a play off because a quartet of reliable backups has afforded them each occasional moments of respite during 60 minutes of battle each Saturday.
Kona Schwenke (NG/DT), Tony Springmann (DE/NG/DT), Sheldon Day (DE/DT/occasional NG), and Ishaq Wiliams (Cat/DE) produced a combined 57 stops including 10 for lost yardage with six QB hurries, a forced fumble, and pair of passes defensed. A member of their second unit earned Irisheyes.com game balls on six separate occasions in 2012 -- each appearing once.
"We'll definitely have six," said Elston in August of his defensive line rotation that did not include the Cats (Shembo/Williams) in the conversation. "We can do anything we need to do based on our personnel. We can go right-left, we can go inside-outside, everyone of them has the capability to move around."
And everyone of them made it possible for the Irish to finish the gauntlet that was the 2012 regular season unscathed.