Last time Oklahoma's defense took the field, it got shredded during a national semifinal loss to Alabama.

It was an all-too-common occurrence last season — the Sooners' dynamic offense often pulled more than its share of the load while the defense struggled.

Enter new defensive coordinator Alex Grinch. The man who previously rebuilt Washington State's defense and more recently was co-defensive coordinator at Ohio State is bringing his aggressive approach to Oklahoma. His first step has been building confidence for a unit that ranked among the nation's worst last season.

"The outside world doesn't see the summer workout on a Monday morning," Grinch said. "They don't see that progress. But we as coaches do. So it's important for us as coaches to highlight it."

Living in the present and looking toward the future will be important for a program that failed to win national titles with Heisman Trophy-winning quarterbacks Baker Mayfield and Kyler Murray. The Sooners have another standout quarterback ready to go in transfer Jalen Hurts, but the defense will be heavily scrutinized and could be the key to the season.

A year ago, the Sooners went 12-2 and won another Big 12 title. But it wasn't done on the shoulders of the defense, which was ranked No. 114 at the end of a lackluster season in which it gave up 454 yards per game, struggled at home in an overtime win against Army and surrendered 48 points in a loss to Red River rival Texas.

Returning players have heard the criticism.

"It motivates you a lot," junior linebacker Kenneth Murray said. "Obviously being a kid in today's society, it's really unrealistic to say that you block out all the noise. Social media is everywhere. People are talking everywhere. So obviously, you hear some of it."

The Sooners are trying to keep their focus on small things that they can control.

"Every play is a new start," defensive back Brendan Radley-Hiles said. "It's a next rep mentality. Do what you do. If you mess up, mess up full speed. Get in the film room, get your feet back. Onto the next rep."

Murray, the Big 12 preseason Defensive Player of the Year, averaged a team-best 11.1 tackles per game last season. Senior defensive lineman Neville Gallimore had 50 tackles, including 5.5 for loss. Senior defensive lineman Kenneth Mann, a team captain last season, had 50 tackles.

The Sooners took a hit last week when starting defensive back Tre Norwood suffered a season-ending injury. But most of the unit returns, and the same faces are committed to producing different results.

"It's a completely new year," Murray said. "I really like the way the guys have been attacking this year. I really expect a great season."

JALEN'S TURN

Hurts is primed to fill the void left by Kyler Murray. He transferred from Alabama after playing in three national title games for Alabama, and is the Big 12 Preseason Newcomer of the Year. He was responsible for 71 total touchdowns for the Crimson Tide. Tanner Mordecai, a redshirt freshman, and Spencer Rattler, a true freshman, are competing with him.

GROUND GAME

The Sooners' ground game might be more prominent this season as a new quarterback settles in. Oklahoma has a dynamic duo back in running backs Kennedy Brooks and Trey Sermon. Brooks ran for 1,056 yards and 12 touchdowns as a freshman last season. Sermon ran for 947 yards and 13 scores last season. T.J. Pledger could make a push for more action this season after rushing for 179 yards last season. Hurts ran for 1,976 yards in his career at Alabama.

NOT-SO-LITTLE LAMB

Cee Dee Lamb is one of the nation's top returning wideouts. The 6-foot-2 junior caught 65 passes for 1,158 yards and 11 touchdowns last season, and is the clear top returning target now that Marquise Brown is in the NFL. Lamb is part of a loaded receiving corps that should help ease the transition from Kyler Murray. Lee Morris caught eight touchdown passes last season and Grant Calcaterra was an All-Big 12 tight end. Charleston Rambo had 74 yards receiving and a touchdown in the national semifinal against Alabama.

GRINCH MENTALITY

Grinch hasn't shied away from telling the Sooners his thoughts about their shortcomings — something Radley-Hiles embraces.

"He's not going to sugarcoat anything," Radley-Hiles said. "He's going to make sure he tells you to your face. He's not going to go around about it or anything like that. He's a grown man. And you've got to be a grown man to play for him."

FAMILIAR FOE

Oklahoma opens with Houston on Sept. 1 and will face coach Dana Holgorsen, who left West Virginia after last season. Oklahoma defeated West Virginia 59-56 last year in the regular-season finale.

"Obviously, we know Dana's reputation — well-deserved reputation as a coach and offensive mind, and he's put together a great staff there," Sooners coach Lincoln Riley said. "It'll be a challenge. It's always fun to play a really, really good opponent first."