ALLEN PARK, Mich. -- Louis Delmas sat on his stool in the Detroit Lions' locker room the other day, and a couple of seats over, Glover Quin’s head shot up from his phone.

Delmas was continuing his running joke of calling Quin “slow," even if they both ran comparable 40-yard dash times at the 2009 NFL combine.

This is no insult to the teammate whom Delmas trusts implicitly, but rather a compliment to his complement in the Detroit secondary and what he has learned from him. Slow, you see, doesn't mean what it sounds.

“It’s crazy because he plays, he’s always in the right position to make plays on the ball and I always wondered why,” Delmas said. “He plays fast, but slow with his eyes. Sometimes you look at him on film and it makes it look like he’s playing very slow, but he’s always in the right position.

“That’s something I always struggled with because I always thought, ‘I need to get there, need to get there, need to get there.’ By watching him, an older guy as far as more experience and playing more games than me, being in the organization he was in, he learned that a long time ago.”

As Delmas was explaining, Quin shook his head at him. Delmas barked back at Quin.

Welcome to the playful friendship that has been all positive for Detroit’s defense.

Delmas kept going, animatedly describing how watching Quin taught him that quickness is more important than speed. How reading the play correctly is paramount to being there first and hopefully on time.

As Delmas is having arguably the best season of his career -- he said he won’t say that until he makes it through the year healthy -- some of the success is attributable to Quin. Same for Quin to Delmas, even if they have as opposite personalities as you could find.

Quin is the consummate professional, quiet, disciplined, focused and consistent. Delmas is the fiery, energetic, passionate soul of the Detroit defense.

Or, as defensive-backs coach Marcus Robertson put it, Delmas is the “spark plug,” while Quin is the “quiet storm.” Even the titles of their positions, with Delmas as the free safety and Quin the strong safety, fit their disparate personalities.

However it happens, it has worked for the Lions. Delmas and Quin are third and fifth on the team with 30 and 26 tackles, and both have two interceptions. Delmas has six pass breakups. Quin has five. Similar stats. Different approaches.

“Too much of anything isn’t good,” Quin said. “So if me and [Delmas] both had the same personality, it might not be good. We might bump heads. If we both played the same way, it might not be good.

“We need to balance.”

With the balance comes trust, and that came instantly when Detroit signed Quin from Houston in March. Delmas was still home rehabilitating his injured knees, but he and Quin texted and called each other, expressing their mutual excitement at playing alongside one another.

There was never any concern, just the comfort that Delmas would finally have the same player next to him every day and that Quin would have a counterpart with the confidence to make plays.

Even as Delmas dealt with injuries the past two seasons, he was a constant presence when he was able to play. Next to him, though, the only consistency Detroit had was a lack of it. Through Delmas’ first four seasons in the league, the Lions had what Detroit coach Jim Schwartz called a “revolving door” playing next to him.

When you’re trying to build cohesion in a group and communication to the point of comfort, the always-changing safeties weren’t safe at all. Delmas never slid into complete familiarity and trust with anyone he played next to as the last part of protection in the Detroit defense.

“For such a long time, Lou hadn’t had that consistent counterpart there,” Robertson said. “When we made the initiative to go out and get GQ, I think that was one of the things that truly helped him out because he knew he was going to have somebody there beside him that he could depend on. Somebody he could count on, somebody that was going to have his back.”

In Quin, Delmas got a counterpart he had known since he entered the league -- they first met at the 2009 combine -- and someone he trusted immediately. He also had someone who, even though they have the same number of years in the league, he could look up to.

Delmas learned that he needed to bolster his physical skills by understanding everything else. And communication is key. Delmas and cornerback Rashean Mathis are consistently telling each other “keep me in it” or “talk to me, talk to me, talk to me” as a way of picking up on any changes they might notice before, during or after a play.

More important is the way Quin and Delmas communicate together.

“They communicate a lot off the field, on the field, you can see,” defensive coordinator Gunther Cunningham said. “Lou probably played some of his better games this year. He’s not gambling as much. He’s playing the system better, and he knows he’s got a guy on the other side.”

That guy is Quin, whom Delmas describes as a “very quiet, humble dude.” Then, he added, “you’ve got me. The fireball.”

And while Delmas has learned from Quin, he is also rubbing off on his strong safety.

“I’m pretty sure, I’m definite, that I’m feeding off of him a little bit,” Delmas said. “Because every time I get in his face and getting riled up, I can see him hopping around a little bit, getting excited.

“We’re different, very much different.”

For Detroit this season, that’s working out just fine.