No. 8 USC escaped with a narrow 48–41 win in Boulder on Saturday afternoon against Colorado, but nearly blew a four touchdown lead, thanks in large part to another questionable defensive performance.

USC defensive coordinator Alex Grinch has been at the center of questions surrounding the ceiling of Lincoln Riley-coached teams, as his defenses have never quite held up their side of the bargain dating back to Riley’s teams at Oklahoma.

Saturday was yet another data point of Grinch’s defense potentially holding Riley and the Trojans back. USC allowed 564 yards of total offense and yielded a 50% conversion rate on third down to the Buffaloes, and that’s before even discussing the seven touchdowns allowed defensively.

USC coach Lincoln Riley stood by his embattled defensive coordinator Alex Grinch after an ugly second half for the Trojans against Colorado.

Rob Gray/USA Today network

Riley came to the defense of Grinch after the game, saying that he still had confidence in his defensive coordinator.

“Yes, I do,” Riley said when asked if he still had confidence in Grinch.

The Trojans have a tackling issue all over the field, and a physicality issue up front. The talent of Caleb Williams and the star-studded USC offense will carry it through the regular season, but as long as this defense remains a sieve, it’s hard to imagine the Trojans being a serious contender for a national championship.