Mason Cobb posted six tackles and two tackles for loss in his debut as a member of the Trojans.

USC won its opener Saturday evening, 56-28 over San Jose State. New players flashed. Star quarterback Caleb Williams picked up where he left off a year ago. But there was some frustration from all sides after the game. Williams said the offense has things it needs to work on.

Cobb said the same of the defense.

“There is a lot to work on at practice this week,” the starting linebacker said. “But the sky is the limit for this defense. You saw those plays where we are all on our stuff. We are just trying to make sure we limit those mistakes.

“A lot of the mistakes we made were self-inflicted. A lot of the plays were right there. We just have to finish them. But, man, we’ve got a lot of work to do.”

Head coach Lincoln Riley agreed.

One play in particular seemed to irk Riley more than most. USC got caught in a coverage bust at the end of the first half and the Spartans connected for a touchdown that made it a 21-14 game going into the break.

At that point, Riley was already hot over the previous offensive possession for USC that went backward and ended in a punt. The Trojans got the ball with under two to play and had a chance to double up. Getting the ball to start the second half, USC could have taken firm control of the evening with a drive for a score. It led 21-7 at that point.

But the offense went three-and-out and punted to SJSU at midfield with 27 seconds to play. Spartan quarterback Chevan Cordeiro connected with wideout Nick Nash for a 28-yard score with just eight seconds on the clock. Defensive backs got their wires crossed in coverage and left the right corner of the endzone completely uncovered. Nash found the hole in the zone and sent the Trojans into the break feeling a little tighter than they would have hoped.

“I liked the way some of the young guys flew around,” Riley said. We had some young guys that made some young guy mistakes too. That’s, again, a little bit to be expected. We’ve got to continue to grow. Excited about where it can be but we’ve got a lot of work to do.”