Rams know they’ll have to lay it on the line when it comes to stopping Bears’ Khalil Mack

Much of the prime-time focus when the Rams play the Chicago Bears on Sunday night will be on quarterback Jared Goff, running back Todd Gurley and other skill-position players in the Rams’ star-studded offense.

Andrew Whitworth and Rob Havenstein also will be in the spotlight.

The Rams tackles are charged with neutralizing Khalil Mack, the Bears’ 6-foot-3, 252-pound edge-rushing linebacker and the highest-paid defensive player in NFL history.

“He’s a monster,” Havenstein said.

That was true even before Mack joined a Bears franchise whose defenses have been known at times through the last 70 years as the “Monsters of the Midway.”

Mack played in college at Buffalo before the Oakland Raiders made him the fifth pick in the 2014 draft. (The Rams selected offensive tackle Greg Robinson with the second pick.)

Mack had four sacks as a rookie and a career-best 15 in 2015. The next season, he had 11 sacks and was voted NFL defensive player of the year. Last season, he had 10½ sacks.

Like Rams tackle Aaron Donald, the 2017 NFL defensive player of the year, Mack was a holdout during training camp. The Rams, in fact, contacted the Raiders about trading for Mack.

But the day after the Rams signed Donald to a $135-million extension, the Raiders traded Mack to the Bears, who signed him to a $141-million deal.

Now he has a team-best nine sacks for a defense that ranks fourth in the NFL and has helped the NFC North-leading Bears to an 8-4 record.

“He plays with great urgency and juice every single play,” Rams coach Sean McVay said. “He can really bang and turn an edge, and then when he gets close to the quarterback, I mean, he is violently attacking that football.”

Early in the season, Mack lined up on the left side and wreaked havoc on right tackles. But as the season progressed, defensive coordinator Vic Fangio began deploying Mack from the right side, putting Mack in matchups with the left tackle.

Whitworth, a 13th-year pro and four-time Pro Bowl player who plays on the left side, welcomes the opportunity.

“Anytime you play those great rushers it’s a challenge for you,” Whitworth said. “But it’s one you look forward to.”

Havenstein, a fourth-year pro, and Whitworth will not handle the task alone.

Mack’s speed, power and reaction skills require tackles to have help from tight ends, receivers or running backs, offensive line coach Aaron Kromer said. The goal: prevent Mack from taking control of big situations.

“You have to create a situation where he’s not alone, where it’s not one on one,” Kromer said.

The Bears have made opponents pay for those kinds of mistakes.

Consider: They rank 20th in the NFL in offense but are fifth in scoring.

That’s because they lead the league with 30 takeaways, including 21 interceptions. Defensive players have scored seven touchdowns, three by safety Eddie Jackson.

Mack set the tone in the season opener at Green Bay when he sacked DeShone Kizer, forcing and recovering a fumble. He also intercepted a pass and returned it for a touchdown.

So it will be a big test for a Rams offensive line that for the second consecutive season has remained intact.

Whitworth, Havenstein, guards Rodger Saffold and Austin Blythe and center John Sullivan have started every game this season.

They have cleared the way for Gurley — who is making a run for league most valuable player — and protected Goff.

The line gave up only six sacks in the first five games, but has surrendered five in a game three times. Still, the 26 sacks given up is ninth fewest in the NFL.

“Anytime your offense is having this much success and your team is 11-1, you’re obviously doing some things well,” Whitworth said.

When the NFL released the schedule last spring, it looked as if the Rams would face Mack in the opener against Oakland. But his trade to the Bears reset the date for Week 13.

“We avoided him Week 1 and now we got to face him,” said Goff, who expressed confidence in Whitworth’s and Havenstein’s ability to protect him.

“Quarterbacks best friend,” he said, “having guys like that and being able to trust them on both sides.”

Bears coach Matt Nagy schemed against Mack for four seasons, two as the Kansas City Chiefs’ quarterbacks coach and two as the team’s offensive coordinator.

Mack had 5½ sacks in eight games against the Chiefs.

So Nagy is happy to have Mack on his side.

“We’re certainly loving the fact that he’s on our team,” he said. “He’s been everything and more than what we thought.”

Whitworth and Havenstein did not wait until Wednesday to begin preparing for Mack.

On Monday, the day after returning from a Week 13 victory at Detroit, they huddled in the film room.

“He’s a special player and special talent,” Havenstein said of Mack, “but, you know, you don’t want to overdo it in your head because you’ve still got to go out there and block the guy.”

With a victory, the Rams can clinch a wild-card-round bye and stay on track to possibly have home-field advantage through the playoffs.

Havenstein is not looking that far ahead.

“I have my hands full,” he said, “so I’m going to worry about the Bears.”

And Mack.

“Wherever he is,” Havenstein said, “we’ll have our antennas up.”

gary.klein@latimes.com

Follow Gary Klein on Twitter @latimesklein