Jeffrey D. Allred, Deseret News
BYU quarterback Tanner Mangum fumbles the ball against Portland State in Provo on Saturday, Aug. 26, 2017. The Cougars look to rebound from a sluggish offensive outing in the opener but know it won't be easy against LSU's vaunted defense.
It’s when we miss assignments and miss blocks and receivers don’t run crisp routes that it comes back to bite us. It’s making sure we learn from that and be more sharp and be more physical. If we’re more consistent, we’ll have more success. —Tanner Mangum

BYU (1-0) vs. No. 13 Louisiana State (0-0)

Saturday, 7:30 p.m. MDT New Orleans Superdome

TV: ESPN

Radio: 1160 AM, 102.7 FM

PROVO — In the season opener, BYU’s offense didn’t exactly put up the type of numbers it was hoping for against FCS opponent Portland State.

The Cougars gained only 13 first downs, threw for fewer than 200 yards, converted just four of 13 third down opportunities and scored only two touchdowns, finishing with a meager 20 points.

When BYU battles No. 13 Louisiana State Saturday (7:30 p.m., MDT, ESPN) at the Superdome in New Orleans, it will be facing one of the nation’s premier defenses.

“Much tougher opponent this week,” said offensive coordinator Ty Detmer.

Last season, the Tigers ranked No. 10 nationally in total defense (314 ypg), No. 13 in rushing defense (117.23), No. 15 in pass efficiency defense and No. 23 in pass defense (197.2).

True, there are new a lot of new faces this season on LSU’s defense and star linebacker Arden Key isn’t expected to play Saturday as he continues to recover from shoulder surgery, but the Tigers are stacked with talent.

“They’re tough. Their strengths are their team speed. They are good players. They’ve got NFL first-rounders every year on that defense,” Detmer said. “It’s no different this year. They lost a few of those guys but every year they reload and the next guy steps in and picks up where that guy left off.”

How will the Cougars combat LSU’s athleticism?

“You’ve got to be really efficient, you’ve got to play fast and you’ve got to be sharp. You can’t be thinking and running and trying to get open,” Detmer said. “You’ve got to know where you’re going and get there quick. They’ve got great team speed and size. They have everything. There were 16 touchdowns scored on them last year in 12 games. We’ve got our work cut out for us.”

While some of BYU’s offensive struggles last Saturday could be attributed to first-game issues, the Cougars know they need to improve quickly in order to hang with LSU.

“Practices have been really sharp, making sure we’re crisp in our routes and blocking schemes and being more dialed in than we were,” said quarterback Tanner Mangum. “We obviously know we can play better. Saturday wasn’t our best game. But you’ve got to move on and learn from it. I’m excited to see our effort. We’ve been working hard this week.”

The offense committed costly penalties last week, negating a long run by Kavika Fonua and, later, nullifying a Fonua touchdown run. Offensive linemen committed chop-block penalties, wide receivers had trouble at times breaking man-press coverage, and Mangum had some errant throws.

Still, there were some positive signs.

Squally Canada ran 16 times for 98 yards and a touchdown while Fonua finished with 59 yards on seven carries.

“Kavika looked really good for his first game at running back,” Detmer said. “He broke some tackles and was good inside the tackles and found some extra yards. He was a pleasant surprise, being his first game.”

Canada is hoping the Cougars can establish a ground game against LSU.

“The best way to beat these cats is to run in between the tackles with low-pad level,” he said. “These cats are 6-feet, 6-3. I’m only 5-9, 5-10. If I can shrink down to 5-5 and run in between my linemen, it’s going to be hard to tackle me. This week in practice I’ve worked on my patience and pad level. Patience and pad level will win the game.”

Tight end Matt Bushman’s debut was impressive as he caught three passes for 56 yards.

“We’re going to try to continue to find ways to get him the ball,” Detmer said of Bushman. “We’ll see a little more of a workload for him. He’s a guy that made some plays for us so we’ll give him more opportunities.”

As for Mangum’s performance last weekend?

“It was pretty good. First game out, a lot of times guys start a little jumpy. But I thought he settled in,” Detmer said. “There were opportunities down the field that maybe we missed as well that we were close on. Overall, he played pretty well. He managed everything really well. He was poised and executed. Now we need to clean up the little things.”

Mangum is hoping that the offense can make significant improvement from Game One to Game Two.

“It’s when we miss assignments and miss blocks and receivers don’t run crisp routes that it comes back to bite us,” he said. “It’s making sure we learn from that and be more sharp and be more physical. If we’re more consistent, we’ll have more success.”