CHARLOTTE — When the Panthers talk about fixing their once-good run defense, they talk about how it takes all 11 players.

When defensive tackle DaQuan Jones sees his phone ringing this week, he knows it's probably Derrick Brown, because they're taking the challenge personally.

"Yeah, it really comes down to the guys up front doing their job," Jones said. "Me and Derrick have to take the load and realize we've got to do a better job up front. Better hands, better knock-back, stuff like that we can get fixed. At the same time, we know to stop the run takes all 11.

"But up front, we've got to make sure we do our job and handle our own, and make sure we're in the right gaps and doing our proper keys."

Through the first three weeks, the Panthers were generally in the right spots, leading the league and allowing 45.0 yards rushing yards per game. The Cowboys blew a hole in that number with 245 on the ground in their first loss. The Vikings hit them the same way for 198 and now they rank 15th in the league in that category.

Defensive coordinator Phil Snow pointed out that was largely a function of two top running backs in Ezekiel Elliott and Dalvin Cook, but the danger is that it created a blueprint for future teams to try to follow. Because the Panthers are built for speed rather than power (and because they're without injured linebacker Shaq Thompson at the moment), teams are learning to lean on the Panthers a bit more.

"We have a lot of guys playing, doing a good job in the run game, and one guy doesn't play his gap properly, and the ball's been coming out," Snow said. "We've got to shore that up, and everybody's got to protect their gaps and stay in their gaps.

"We did a good job of that the first three weeks; we have not done a good job of that against Dallas and Minnesota. Got to get that shored up."

Too often lately, those yards have come between the tackles, which is why Jones and Brown are putting in overtime this week to fix things.

"You have to have the mindset that we don't need the linebackers and safeties to stop the run," Jones said. "You have the mindset we can stop the run with just four. Clearly, we didn't do that the last three weeks.

"We've been beating ourselves up about it, and trying to beat it into our minds and bodies, to make it a mindset that we're going to go out there and be a physical group up front and stop the run."

Jones said Brown has been calling him each night this week, talking through the small things they see on film when they leave the office. And as Brown develops, he's learning some of the minutiae of football from Jones, an eight-year veteran who was brought here in part for his ability to share that knowledge.

"When I sit there and watch film, I watch film different," Brown said. "But when we sit there together, it's beneficial because I'm learning from him. He's teaching me things I've never seen before."

Specifically, Jones is talking to Brown about pre-snap indicators — the small tells which can tip off a play.

"A lot of time, I spend a lot of time watching the play, and DaQuan is breaking down the play before it even happens," Brown said. "A lot of great defensive linemen, that's what they'll tell you to do first. But until you really have someone who will sit down with you and teach you how to do it, it doesn't really matter.

"It was something, over the years I heard people talk about it, and our coaches (in college) pressed it on us, but it's something I never could get a grasp of. Back in college, it's class, football, class, football. Now with this, this truly being my job, it's a whole 360. And more so the learning aspect which comes from the football. That's been the biggest thing with me; the classroom is the meeting room at this level. For me being able to sit there and watch film and be able to see certain things is very beneficial to how I play on Sunday."

Jones relishes teaching Brown those small details, such as how a runner is set in the backfield, or how a center's split (the space between him and the guard) can suggest the play to come or the direction he's planning to go with his block.

"Sometimes it takes a third set of eyes," Jones said. "The coaches all have so many players to coach, stuff like that. Derrick's chipping away at it, every week learning more and more, and seeing what he needs to do. . . .

"You can't run every play from the same stance and the same alignment. Everyone cheats a little to get the job done. If you can pick up on that early in film study, it can really help you out."

If they can stabilize the middle of the run defense, the hope is that some of the other defensive discrepancies won't be as glaring. They gave up nine plays of 20 yards or more last week against the Vikings, and after posting 14.0 sacks the first three weeks, they've only had 2.0 sacks in the most recent three games, with Haason Reddick getting both of those and Brian Burns on a bit of a cold streak.

Those are the kind of big, obvious numbers people notice.

Jones knows that if he and Brown can provide a better anchor in the middle, some of those flashier numbers could return.

"When you put your hand in the ground, you know not going to be all glitz and glamour," Jones said. "You have to earn the right to rush. We have to do our job on first and second down and stop the run, then we get to have fun and get after the quarterback.

"For me, it's a mentality to go out and do our job, then Haason and Burns and Morgan Fox can pin their ears back and go. We get back to doing that; we'll be OK."