Over the next three weeks, the so-called “soft” portion of the schedule, the Dolphins’ defense will face perhaps its biggest back-to-back test of the year when they visit Detroit and Chicago and host Cleveland.

The Lions, led by running back D’Andre Swift, who looks set to return from a shoulder injury this week, are seventh in the league in rushing (145.7 yards per game). The Bears are first (181 ypg) in rushing and the Browns are fourth (163.6 ypg).

Fortunately for the Dolphins, their run defense is strong, ranking 8th in the league at 103.3 yards per game but 21st in yards per attempt at 4.2.

And what you’re seeing now from the Dolphins defense is the culmination of several years of improvement.

Coach Mike McDaniel revealed part of the not-so-secret formula for this year’s success.

“Collectively, it was our commitment to get better, to be proud of that,” he said.

And while they lost safety Brandon Jones, the team’s leading tackler (49), to a season-ending knee injury last week, the Dolphins expect their run defense to continue its promising run.

The big key for Miami is what style, or how many styles, it plays this week without Jones, who is usually eighth in the box for eight-man fronts that stop the run so often and so effectively. He’s also their best blitzer.

“When you have really good players that you lose, you don’t replace them with one player,” McDaniel said. “You use other players on your roster and then you run your scheme around what they do well, so that’s the whole point and everyone on defense knows we have to step up for his lost production.

“But this is not one person. This is a collection of Miami Dolphins quarterbacks. Different players, different skill sets and you try to use them as best you can to give them a chance to succeed.”

The Dolphins are expected to use a combination of guards Clayton Feidelem, Eric Rowe and possibly rookie Verone McKinley III, who will have to come off the practice squad again to pair with sophomore guard Jevon Holland.

Detroit is equipped with a skilled offensive line led by center Frank Ragnow and Pro Bowl guard Jonah Jackson, who is listed as questionable with a neck injury. They do a good job. Lions running backs rank third in the league in yards per attempt (3.4 yards).

But the Dolphins defense is growing.

Last year, the Dolphins finished 13th behind Buffalo in passing defense at 109.8 yards per game. That total could have been slightly better, but Tennessee rushed for 198 yards late in the season. But it was still an improvement.

In 2020, the Dolphins were 16th in passing defense at 116.4 ypg.

In 2019, the Dolphins were 27th in passing defense at 135.4 ypg.

In 2018, the Dolphins were 31st in passing defense with 145.3 ypg.

Whether it’s defensive linemen Christian Wilkins and Zach Siler setting the tone up front, outside linebackers Andrew VanGinkel, Jaylon Phillips and Melvin Ingram setting the tone, or linebackers Elandon Roberts and Jerome Baker clamping down on balls, the Dolphins’ defense is steadily improving.

It takes a cue from defense as a whole.

“We have a standard,” Van Ginkel said. “If we’re not closing teams down and keeping teams out of the end zone, we’re not doing a good enough job. And we all hold each other accountable and proud.”

Yes, there were some breakdowns on the Dolphins defense.

Baltimore rushed for 155 yards, led by quarterback Lamar Jackson’s 79-yard touchdown run. Buffalo, led by quarterback Josh Allen’s 47 yards and Zach Moss’ 46 yards, rushed for 115 yards. The New York Jets, led by now-injured running back Brice Hall’s 97 yards, rushed for 135 yards.

But for the most part, the Dolphins have been good defensively, and that will be vital in the next three games.

“No matter what, you always have to stop the run,” Siler said. “The biggest thing we say is, ‘You stop the run before you make the pass.’ That’s what we preach here and always preach.”