Penn State linebacker Alex Tatsch missed the Oct. 10 loss to USC with a practice injury, and coach Matt Campbell said Tuesday the team still did not know the diagnosis or timetable before its Oct. 17 game at Michigan.

Tatsch appeared as questionable on the Big Ten availability reports Wednesday, Oct. 7, and Thursday, Oct. 8, before Penn State ruled him out Friday, Oct. 9. He had been one of four linebackers playing regularly through six games.

Tony Rojas, Kooper Ebel and Cael Brezina now must take on more work as Penn State tries to halt a three-game skid at Michigan without letting an already thin defense become a roster problem.

Campbell offered no return range for Tatsch.

> “Alex's situation is tough. He got injured in practice. We still don't know exactly where that is or how long that's going to be,” Campbell said. “Hopefully we'll know a little bit more this week. I think you guys all know what Alex means to that linebacker room.”

Penn State has not disclosed Tatsch’s injury, whether he can play at Michigan or the linebacker combination that will replace him.

Tatsch logged 81 snaps in four games, with 11 tackles, 1.5 tackles for loss and a sack. Those snaps came from a rotation of only Tatsch, Rojas, Ebel and Brezina, leaving little room for another absence.

Rojas leads Penn State with 43 tackles, four sacks and two interceptions. Ebel has 33 tackles and a sack, but his eight missed tackles lead the team. Brezina has 22 tackles while filling a backup role similar to Tatsch’s.

The defense already had nine players among the 13 ruled out before USC on Oct. 10. Linebacker Cam Smith is working back into practice, while defensive end LaVar Arrington II was trending toward a return after Penn State’s open date before the Oct. 31 Purdue game. Defensive end Max Granville is expected to miss the season after a practice injury before the Sept. 12 game at Temple.

Penn State allowed 22 points while opening 3-0, then gave up 24 to Wisconsin, 34 to Northwestern and 31 to USC in the three losses that followed. At 3-3, the Nittany Lions need their available linebackers to carry a larger share against Michigan.

The problem extends beyond Tatsch’s 81 snaps. Four players made up the regular linebacker rotation, and the next options have far less game experience.

Redshirt senior John Klosterman has played in 30 games and recorded 18 tackles and one sack across four seasons at Iowa State. West Virginia transfer Chris Fileppo played in 12 games as a freshman in 2025, making 12 tackles and one tackle for loss.

Keian Kaiser, Josh Banks and Evan Wolff have not played in a college game. All three are freshmen; Kaiser entered as a three-star recruit, while Banks and Wolff arrived unranked.

Rojas, Ebel and Brezina are the immediate larger-role options, though Penn State has not named its starting combination for Michigan.

Rojas supplies the playmaking. Ebel and Brezina have the production to stay in the rotation, but Ebel’s missed-tackle total puts more pressure on the group when every available linebacker may have to play more.

A defensive role for Klosterman or Fileppo would give Penn State a fourth linebacker with college experience. Turning to one of the freshmen would underscore how quickly the depth chart has narrowed.

Tatsch’s absence does not erase Penn State’s chances at Michigan. Rojas has been the defense’s most productive player, and Ebel and Brezina have already handled meaningful work.

But Penn State entered the USC game with nine defenders unavailable and then lost one-quarter of its regular linebacker rotation. Michigan is the immediate test because any help from Smith or Arrington is more likely to come after that game.

1. Who joins the three-man core? Defensive statistics for Klosterman or Fileppo would show Penn State used a fourth experienced linebacker.

2. Can Ebel cut down the misses? His tackling against Michigan will be a direct follow-up to his team-high eight missed tackles through six games.

3. How much does Brezina play? A larger role would show Penn State sees him as the closest replacement for Tatsch.

Campbell framed the decision Tuesday: “Making sure we've got the right depth there is going to be really critical. Do we have it? Are guys available? What does that look like? I think all those things certainly matter right now for us.”