Biggest problem with USC defense is not hard to figure out

The problem with USC’s defense, which failed to keep the Trojans in last week’s game at Texas, was pretty simple for the coaching staff to diagnose.

Time and time again, USC had the Longhorns exactly where it wanted them after two downs. But on four of Texas’ six scoring drives, it converted at least one third down of eight or more yards. On another drive, Texas quarterback Sam Ehlinger turned third and 10 into fourth and one with a scramble, and the Longhorns converted the fourth-down play.

The biggest breakdown came on the first drive of the second half, with Texas leading 16-14. On third and eight, Ehlinger found Lil’Jordan Humphrey for 10 yards with Marvell Tell III on the coverage for USC. Later in the drive, on third and seven, Ehlinger hit Devin Duvernay for nine yards with Isaiah Langley in coverage. Texas eventually scored a touchdown to take a 23-14 lead and keep the Trojans on their heels.

“It’s been different things, uncharacteristic things of some veteran guys that made mistakes,” USC defensive coordinator Clancy Pendergast said Tuesday. “We’ve had some young guys make mistakes. We just have to do a better job of recognizing where we are on the field and what the situation is and how important it is to get off the field on third downs.”

The Trojans held Nevada Las Vegas and Stanford to a combined nine of 28 (32%) on third-down conversions, so it came as a shock that Texas went 10 for 19 and converted in so many crucial moments.

“We always want about 30%,” Pendergast said. “But last week was not nearly as good as what our standards are.”

Based on stats alone, it would appear USC’s defense could get some help this week in facing a Washington State team that, despite its 3-0 record, has converted just 10 of 37 third downs — 125th nationally.

That stat, though, doesn’t tell the whole story.

“They are a four-down team,” USC coach Clay Helton said. “In three games, they’ve already gone for it on fourth down 11 times. You really have to be able to play them as a four-down team. So we got some extra third-down work, especially on defense today.”

Washington State and coach Mike Leach are known for being relentless. The Cougars are eight for 11 on fourth down, which is tied nationally for the second-most conversions.

Punting with a glitch

Special teams coach John Baxter said punters Reid Budrovich and Chris Tilbey have “got a little bit of a funky rhythm they’ve fallen into.”

“It’s just one of those things that’s probably not unlike a golfer or a batter or anything else,” Baxter said. “You end up with a little glitch here and there, and you figure out what the source of it is, you work through it and you get rid of it.”

Baxter said he’s spent more time with them this week in hopes of getting them back on target.

“Adversity kind of introduces a man to himself,” Baxter said, “and this is when they need each other and they need me. That’s teaching and coaching, in a nutshell.”

Helton said the first thing he did upon returning to campus Sunday was watch all three games. He specifically zeroed in on the punting.

“Made sure it wasn’t scheme, or fundamentals, and technique in coverage,” Helton said. “It’s just poor kicks. We wanted to make sure of that, and it turned out that way.”

Etc.

Helton said that defensive tackle Brandon Pili did not start against Texas because he was late for a team meeting. … Left tackle Austin Jackson missed practice Tuesday because of illness, but Helton expects him back Wednesday.

brady.mccollough@latimes.com

Twitter: @BradyMcCollough