Lincoln Riley, the head coach at USC, defends his decision to keep Alex Grinch.

After a dismal end to the season for USC’s defense cast some doubt on his coordinator’s future, coach Lincoln Riley has elected to stay the course with Alex Grinch.

Riley made that decision official Tuesday, offering a vote of confidence in his defensive coordinator amid pleas from frustrated fans who spent the last week calling for his ouster.

“I know what he’s made of,” Riley said of Grinch. “I now what’s getting ready to happen defensively. And so, I just have a confidence and a belief there, not just in Alex, but the other guys in the room.

“I’ve been through it enough with that guy to know, don’t bet against him.”

The final month of USC’s season had offered little reason for optimism about the direction of its defense. USC allowed nearly 2,000 yards over its final four games, unraveling at the most inopportune point of its season.

The defense was dominated by Utah in the Pac-12 Conference title game, erasing any hope of what had been an improbable run to the College Football Playoff. But the nadir didn’t come until last week, when USC fell to Tulane in the Cotton Bowl, giving up more than 10 yards per play as the Trojans relinquished a 15-point lead in the final five minutes.

In the lead-up to that defeat, Grinch was asked how much he believed USC’s defense had accomplished in his first season as coordinator.

“The answer is, ‘Not enough,’” he said. “You’re charged with having a championship-level defense at USC. You signed up for that. We played good enough defense 11 times. We didn’t play good enough defense two times, but I don’t take a lot of solace in that. We were expected to have a championship-level defense, and we weren’t able to do that in the ’22 season.”

By retaining Grinch, Riley is betting on that leap to championship level taking place next season. But considering how much of its top talent USC has already lost on defense, it could be an uphill climb for the Trojans’ embattled coordinator.

USC will be without at least its top defensive lineman from last season, Tuli Tuipulotu, and its top cornerback, Mekhi Blackmon, who have declared for the NFL draft.

USC has added five transfers on defense, including All-Big 12 linebacker Mason Cobb from Oklahoma State. Whether it’s enough to weather the loss of its two most impactful defenders remains to be seen.