It would be a mistake to overlook the Cotton Bowl running backs

Friday’s Cotton Bowl will feature two of college football’s top quarterbacks, USC’s sure-armed Sam Darnold and Ohio State’s J.T. Barrett, a dynamic dual threat.

Yet the offensive weapon both defenses fear is the opposing running back.

Junior tailback Ronald Jones II has averaged more than six yards a carry in three seasons at USC, and he ran for 814 yards and 10 touchdowns in his last five games. Ohio State freshman J.K. Dobbins has rushed for 1,364 yards and averaged 7.5 yards per carry.

“I don’t think our biggest key is to stop the pass,” said USC linebacker Cameron Smith, who led the Trojans with 102 tackles this season. “J.K. Dobbins is the key to their offense right now. They’re going to come out and try to pound the ball against us.

“Our most important thing is to stop the run. If J.T. Barnett beats us with his arm, applause.”

Ohio State coach Urban Meyer was equally complimentary about Jones.

“I know we’re talking about Sam. But their tailback, I started watching him on videotape and it’s hard to say he’s not as good,” Meyer said. “This guy is outstanding.”

Heavy wait

USC hasn’t played since the Pac-12 Conference championship game on Dec. 1; Ohio State’s last game, the Big Ten title game, was a day later.

Darnold, who arrived in Texas with his teammates a week ago, said he’s anxious to get back on the field.

“It’s been a few weeks now,” he said. “I’m definitely ready to play this game. We’ve been in Dallas for a few days, so a lot of waiting around and waiting around.”

However, the break has allowed players to recover from minor injuries, adding to the depth of each team.

“We’re going to play four tight ends; we’re going to play four running backs; we’re going to play about eight; nine wide receivers. And one quarterback, hopefully,” said Tee Martin, USC’s offensive coordinator.

Parting gift?

Barrett will be appearing in his 50th — and final — game for Ohio State in the Cotton Bowl game, which will be played about 125 miles from the Texas town where he was born.

Despite all the things he and the school have accomplished in his four seasons with the Buckeyes, the biggest trophy he won came in this year’s Big Ten title game.

In 2014, when Ohio State also won the Big Ten championship and a national title, Barrett was hurt. And in each of the last two seasons, the Buckeyes didn’t make it to the conference title game.

“At the end of the day, how you really are measured as a quarterback is [by] how many championships you won,” Meyer said. “So I really wanted to see him get that championship.

“J.T. has done it all for us. Now it’s an opportunity to close out his career in his home state and say he’s a Cotton Bowl champion.”

Family affair

USC coach Clay Helton got his first big coaching job at the University of Houston under his father, Kim, a football lifer who coached for more than four decades, mostly as an assistant.

The elder Helton led the Cougars to just one bowl appearance in seven seasons as a head coach but he had a major impact on his son, who on Friday will be making his fourth appearance as a head coach on the sidelines of a bowl game.

“I learned everything from my dad,” Clay Helton said of his father, who was traveling to Dallas on Thursday. “My dad is my hero, my mentor and I still call him three times a week. Any coach that’s had over 40 years of experience both at the NFL and college level and has that much love and compassion for you, you listen to.

“He’s taught me how to be a husband, how to be a father and how to raise kids in the college game. Very, very blessed to have him in my life.”

Injury report

Helton said linebacker Porter Gustin won’t play Friday. Cornerback Jack Jones will be a game-time decision.

Gustin, who had 68 tackles as a sophomore in 2016, broke a toe and injured a bicep in September and played just two halves — one against Texas, one against Arizona State — the rest of the season.

Jones, a sophomore, started 13 games this year but twisted an ankle in the Pac-12 championship game earlier this month.

Ohio State expects to be at full strength.

kevin.baxter@latimes.com

Twitter: @kbaxter11