Sam Darnold has already impressed Texas defensive players, which isn't an easy thing to do.

In the last few seasons, Texas faced future NFL No. 1 pick Jared Goff, another first-round pick in Patrick Mahomes, a second-rounder in DeShone Kizer and a third-round pick in Davis Webb. And big-time playmakers Baker Mayfield and Mason Rudolph are still around to haunt Big 12 secondaries.

Junior cornerback Holton Hill started his preparation for No. 4 Southern California and Darnold this week. "I was watching him on film," Hill said, "and it was like: 'Wow. Man.'"

Hill isn't alone in his appreciation for Darnold, a 6-4, 220-pound redshirt sophomore. He's won 11 of 12 starts. In half of those games, he's thrown for at least three touchdowns. Darnold combines pro size and an NFL quality arm with an innate ability to extend plays.

Among the voluminous list of complimentary quotes in USC's game notes is UCLA coach Jim Mora comparing Darnold to a bigger Tony Romo.

Said retired college football voice Keith Jackson: "He has some good in his gizzard. He's got some athletic ability, and those are the kind of guys who can beat you."

Texas coach Tom Herman, whose rise has been fueled by quarterback development, said he recruited Darnold when he was offensive coordinator at Ohio State. Darnold actually grew up not far from Herman's mother in Capistrano Beach, Calif.

"The things that impress me are the things that concern me since we're playing against him," Herman said.

How concerned? When Herman checked in on the defensive preparation earlier this week, he compared it to the briefing scene from the asteroid disaster movie Armageddon: "So, scariest environment imaginable, right?"

For all his skills, Darnold has been human. Entering this season as the Heisman front-runner with everything that accompanies it (including his own podcast), he has four interceptions in his first two games.

Even though Hill has two interception returns for touchdown this season, Texas ranks 92nd in the FBS in pass efficiency defense and didn't look great in the opener against Maryland.

Hill even sent a message to the front seven this week, saying the defensive backs will need help from the pass rush.

In some ways, the matchup might serve as an early indicator of how Texas might fare against Mayfield or Rudolph or West Virginia's Will Grier, another big-time talent.

"Everybody's basing it off that we don't play good defense," linebacker Malik Jefferson said. "We haven't shown that we've been dominant until last week, that last game. But, of course, people aren't giving us the credit because they're San Jose State.

"I feel like we're going to show up and we're going to do our job, and that's what's going to be taken care of."

Darnold's impact may go beyond numbers. A quick start by Darnold and the offense -- including McKinney North product Ronald Jones II (275 yards rushing) -- could supercharge the first USC sellout since 2013.

"He makes his team better, which is what you ultimately want at quarterback," said linebacker Naashon Hughes. "I've seen him make some throws and celebrate with his guys. I think [his teammates] feed off of his energy."

Twitter: @ChuckCarltonDMN