Right defensive end Kapron Lewis-Moore (knee surgery) is out for the season and the status of his backup, freshman Stephon Tuitt, remains in doubt for Saturday. Tuitt has battled illness since prior to last week' Boston College game, missing the contest vs. the Eagles.
Backup OLB/Pass-rushing end Steve Filer is also out for the season after suffering a knee injury in a mid-November practice.
Defensive LineThe starting front line should include freshman Aaron Lynch, redshirt-freshman Louis Nix, and senior Ethan Johnson, who'll likely again shift to the right side in place of the Lewis-Moore/Tuitt tandem. Nix will be spelled and joined in tandem by senior nose guard Sean Cwynar while freshman defensive lineman Chase Hounshell will also see time along the interior line.
Johnson continues to recover from a severe ankle sprain in what will be his third game back after missing nearly five contests due to the injury; one not close to 100 percent healed entering tonight's contest.
Outside linebackers Prince Shembo and Darius Fleming shift to down positions at defensive end with the line shows a 4-3 front. Lynch and Johnson are capable of moving inside in such situations as is outside linebacker Troy Niklas who served as an interior pass rusher in long down-and-distance situations last week vs. Boston College.
LinebackersNoted above, Fleming (Cat) and Shembo (Dog) man the outside ‘backer positions when the Irish show a 3-4 front. Shembo is spelled in passing situations by safety Jamoris Slaughter, though the Cardinal's oft-used multiple tight end sets would stress what is then an undersized Irish perimeter.
Butkus finalist Manti Te'o mans the middle, flanked by the Will linebacker combination of Dan Fox and Carlo Calabrese. In obvious passing situations, safety Austin Collinsworth occupies the role of Dime linebacker (a sixth defensive back), generally alongside Te'o.
With Niklas' shift to a defensive line role to help the depleted front, few backup linebackers are expected to appear for defensive coordinator/linebackers coach Bob Diaco's unit. Danny Spond is available as the backup Dog 'backer and Kendall Moore is Te'o's technical backup inside, though in good health, Te'o won't miss a meaningful play from scrimmage.
Defensive BacksThe safety trio of Harrison Smith, Jamoris Slaughter, and Zeke Motta, coupled with the cornerback tandem of Robert Blanton (field) and Gary Gray (boundary) perform most of the secondary's heavy lifting, rarely leaving the field. Sophomore cornerback Lo Wood could see rotation time on the edge; the next man in at cornerback is then Wood's classmate Bennett Jackson.
Slaughter, as noted above, shifts to outside linebacker at times and is often employed as a nickel cornerback covering the opponent's slot receiver.