A Notre Dame defense that has overcome key injuries all season must do so again as standout defensive lineman Rylie Mills will miss the remainder of the College Football Playoff with a right knee injury.

Coach Marcus Freeman on Monday confirmed the outlook for Mills, who was injured while sacking Indiana's Kurtis Rourke early in the second half of Friday's 27-17 first-round win at Notre Dame Stadium. Mills, a senior and a captain, leads Notre Dame in both sacks (7.5) and tackles for loss (8.5).

Following the game, Freeman told ESPN's Scott Van Pelt that Mills' injury did not appear to be season-ending and that there was "optimism" Notre Dame could regain him for the CFP quarterfinal against No. 2 seed Georgia on Jan. 1 at the Allstate Sugar Bowl.

Mills' absence stings a Fighting Irish defense that already has lost All-America cornerback Benjamin Morrison and rush ends Jordan Botelho and Boubacar Traore. The defensive line had just regained senior Howard Cross III, who played against Indiana after missing Notre Dame's final three regular-season games.

Junior Gabriel Rubio replaced Mills during the season half against Indiana and finished with two tackles.

Notre Dame got some good injury news as offensive tackle Charles Jagusah, a projected starter at left tackle who sustained a torn pectoral muscle in preseason camp, is available for the Sugar Bowl. He recently began practicing again.

Starting offensive lineman Rocco Spindler, who started against Indiana before leaving with an undisclosed injury, is questionable for Georgia, Freeman said, while linebacker Kyngstonn Viliamu-Asa is also questionable.