Watch the QBs as No. 4 USC takes on Texas

LOS ANGELES -- One of the most famous plays in college football history -- Vince Young's fourth-down touchdown in the 2006 Rose Bowl Game -- took place when the Texas Longhorns played the USC Trojans.

When the two programs meet for the first time since that national championship encounter, quarterback mobility could again provide a key plot point.

Fourth-ranked USC (2-0) welcomes Texas (1-1) to Los Angeles Memorial Coliseum on Saturday night with both teams coming off impressive rushing performances in Week 2. The Trojans went for 307 yards in a win over conference rival Stanford, as running backs Ronald Jones II and Stephen Carr each eclipsed 100 yards on the ground.

Similarly, Texas got a boost in its 406-yard rushing performance against San Jose State with a stellar showing from running back Chris Warren III, who notched 166 yards and two touchdowns on just 16 carries.

But the added versatility both offenses feature with mobile quarterbacks could play an integral role in the Week 3 meeting.

None of the signal-callers who could line up behind center on Saturday are comparable to Young -- few in college football have been -- but either team has the ability to supplement the run game at the position.

USC quarterback Sam Darnold is noted for his NFL arm, but his mobility also has been a central facet of the buzz surrounding his play since taking over as starter last season.

Darnold -- who completed 21 of 26 passes for 316 yards and four touchdowns against Stanford -- mostly uses his nimble feet to elude the pass rush, but he's also shown a willingness to take off if defenses aren't paying attention. He scored his third career touchdown on the ground two weeks ago against Western Michigan.

"You saw in the first game, him actually pulling the ball," said USC coach Clay Helton. "We don't call his number a ton to run the ball, but down in the red zone, we did have an opportunity ... and he scored a touchdown on a zone-read pull.

"Then, this past game, we were able to get a red-zone quarterback draw call that produced yards. Then, we run the option with him for a touchdown. So it definitely helps the (overall) run game."

The threat Darnold adds to USC's power-run approach presents a dynamic that has been problematic for the Texas defense already once this season. Maryland successfully established Tyrrell Pigrome in Week 1, particularly against Texas' pass rush, as the Terrapins pulled off a 51-41 upset.

"They checked to a run and got us," Texas head coach Tom Herman said. "They came up with a bit of an answer, which was to run the quarterback."

Meanwhile, the Texas quarterback rotation features more rushing options than some teams have at running back. Herman, the first-year Longhorns head coach, has played three different quarterbacks through two games -- both by design and by necessity -- all of whom have made contributions in the run game.

Veteran Jerrod Heard moved to wide receiver in the offseason, but a shoulder injury to Week 1 starter Shane Buechele -- who scored a rushing touchdown against Maryland -- presented opportunities for Heard to step back behind center.

Heard largely operated the previous two seasons out of a variation of the Wildcat formation dubbed the "18-Wheeler," but Herman said Heard is more than just a ball-carrier at quarterback.

"We'll always carry a (quarterback) package for him," Herman said. "This is not a guy who's never played the position. ... If people just start cramming the box with bodies, he can at least be serviceable throwing the football."

Heard can supplement the Longhorns at quarterback, regardless if Buechele or Sam Ehlinger starts against USC. Buechele's shoulder wasn't considered 100 percent early this week. Whoever lines up Saturday, the Trojans anticipate a potential two-way threat.

Ehlinger produced 6.9 yards per carry on seven attempts in Week 2 against San Jose State.

"Shane and Sam are very similar quarterbacks," Helton said. "Both have the athleticism to move the chains, both can create."

On defense, Texas defensive back Holton Hill has been a playmaker, with three return touchdowns this season -- two on interceptions and one on a blocked field goal. USC's defense is led by linebacker Cameron Smith, who had eight tackles last week and is strong against the run.