Khalil Mack couldn’t wait to watch and rewatch all that went haywire during the Chargers’ 35-6 loss Nov. 16 to the Jacksonville Jaguars. So, he said he began dissecting the video as the team’s bus departed the stadium for the airport and a cross-country flight home.

Mack didn’t have to do it at that moment, but he was eager to learn what he could from the Chargers’ widest margin of defeat in Jim Harbaugh’s two-season tenure as their coach. He could have waited until after the Chargers’ bye in Week 12 and used it as preparation for Week 13.

But he believed it was best to begin the process of fixing all that went wrong as soon as possible, the better to prepare to face the Las Vegas Raiders on Sunday at SoFi Stadium and for the final five regular-season games to follow. Clearly, something was amiss in the game against the Jaguars.

There was no time to waste. So, Mack, a future Hall of Fame outside linebacker, went right to work.

It wasn’t pleasant. It wasn’t fun. It was work.

“I was on the bus, I watched it on the bus on the way to the plane, and some on the plane,” Mack said earlier this week of reviewing the Jacksonville horror show. “So, just to talk through a lot of stuff and correct a lot of stuff and, yeah, looking forward to this opportunity, the next opportunity.”

What did Mack learn from his video study? How can the Chargers improve after hitting rock-bottom during their loss to the Jaguars?

“Just the details, fine-tuning the details,” he said.

No question, it would be a start for a team with a 7-4 record that didn’t play like a team with a 7-4 record against Jacksonville. The Chargers must get back in sync if they are to defeat the Raiders, as expected, and enter the toughest part of their schedule. The Chargers are 9½-point favorites Sunday.

“Fine-tuning the details,” Mack said again and not for the last time.

It didn’t matter that the Chargers are favored to win by more than a touchdown or that their reeling opponent was 2-9 and fired offensive coordinator Chip Kelly after its latest defeat or that the first meeting between the teams was an easy Chargers victory. Mack believed they must get it right Sunday.

“This is no different than any other week, it’s a game we’ve got to win,” said Mack, a nine-time Pro Bowl selection over his 12 seasons in the NFL.

The Chargers’ stretch run gets more difficult after they face the Raiders. They end the regular season with games against the Philadelphia Eagles, Kansas City Chiefs, Dallas Cowboys, Houston Texans and Denver Broncos, each opponent jockeying for better playoff position.

The Raiders were the Chargers’ sole focus this week, though, and they weren’t sure what they would see from a Las Vegas team that has lost five consecutive, including a 24-10 loss to the Cleveland Browns in Week 12. The Raiders’ only wins were over the New England Patriots in Week 1 and the Tennessee Titans in Week 6. The Chargers defeated the Raiders in Week 2.

A change in offensive coordinators, with Greg Olson taking over for Kelly, meant throwing out the game plan, according to Chargers defensive coordinator Jesse Minter. He said they would approach Sunday’s game like a Week 1 matchup, focusing more on themselves than on the opposition.

“We spent the majority of the bye week looking at ourselves and then the last part of the week we started on the Raiders,” Minter said. “Obviously, you want to be prepared for the things they like (to run). We need to know where the really good players are that they’re going to feature.”

In the final analysis, the Chargers lost the battle of the offensive and defensive lines in their loss to the Jaguars. They failed to protect quarterback Justin Herbert and didn’t apply sufficient pressure on Jacksonville’s Trevor Lawrence while also giving up far too much on the ground.

The Jaguars rushed for 192 yards and four touchdowns on 47 attempts.

Harbaugh said Jamaree Salyer would start at left tackle Sunday, the Chargers’ third different starter as Herbert’s blind-side protector after Rashawn Slater suffered a season-ending knee injury during training camp in August and Joe Alt sustained a season-ending ankle injury in Week 9.

The Chargers also could get a boost on their defensive line if Otito Ogbonnia is sound enough to play against the Raiders. He was listed Friday as questionable to play because of an elbow injury that sent him to injured reserve after a loss to the Indianapolis Colts in Week 7.

“Everybody cares, everybody wants to be good at their work, and that’s what I’ve seen throughout the season,” Harbaugh said of the Chargers’ mindset coming out of the bye week. “The guys came back Monday and I couldn’t have scripted it any better. Every guy was locked in.”

CHARGERS (7-4) vs. RAIDERS (2-9)

When: 1:25 p.m. Sunday

Where: SoFi Stadium

TV/Radio: Ch. 2; 640 AM/94.3 FM (Spanish)