Sprained MCL in his left knee. Not the worst, but these injuries will shelve him for at least 4 weeks.
Godspeed to him, for his recovery.
He could be back in time for the end of the season, and should be available for the playoffs.
Link: https://www.ndinsider.com/story/sports/college/football/2025/10/20/notre-dame-football-injury-report-updates-billy-schrauth-charles-jagusah/86624638007/