SOUTH BEND, IN - SEPTEMBER 02: Greer Martini #48 of the Notre Dame Fighting Irish causes a fumble in the fourth quarter of a game against the Temple Owls at Notre Dame Stadium on September 2, 2017 in South Bend, Indiana. The Irish won 49-16. (Photo by Joe Robbins/Getty Images)

Top Notre Dame defender officially ruled out of USC game

Notre Dame's defense will be weaker against USC.

Notre Dame's defense will be tested in a big way on Saturday, as the Irish play host to an explosive USC offense that features a top-tier quarterback in Sam Darnold and an elite running back in Ronald Jones. While Notre Dame has generally been good on that side of the ball this season, the Irish will be missing a key piece for the big showdown.

Tim O'Malley of Irish Illustrated brings word that linebacker Greer Martini will be on the shelf, leaving a hole on the depth chart for the home team.

"He's out. He's not going to play. I think it's a good chance we're going to have him back for North Carolina State. He had a small procedure done to clean up a small meniscus...he's moving around today pretty good. But we would be rushing to get him back. We'll hold him out this week but we feel really confident we'll get him back next week."

It should be noted that Martini did not start in Notre Dame's last game but, at the same time, he has been a featured linebacker before and is certainly a player that would have seen extended time against USC. In his stead, Notre Dame looks to deploy Te'Von Coney and Jamir Jones for increased time and, in general, the Irish should be okay.

Still, any absence whatsoever against USC is not ideal and it will be interesting to see how Notre Dame adjusts.