SAN DIEGO -- Brandon Mebane was brought in during free agency this offseason to shore up one of the worst run defenses in the NFL for the San Diego Chargers.

Through seven games, mission accomplished.

The 31-year-old nose tackle proved he can still play, doing an impressive job clogging up the middle. The Chargers are allowing just 90 yards a contest, good enough for No. 8 in the NFL.

Last season the Chargers allowed nearly five yards a carry, second-worst in the NFL. This year, San Diego has allowed four yards per rush, No. 16 in the league.

“I’m just trying to do my part and win my one-on-one matchup, or if I’m getting double-teamed, to try and get movement,” Mebane said.

Mebane has 16 tackles, a sack and an interception through seven games. He’s played a total of 229 snaps, averaging 33 snaps a contest.

Mebane also was voted defensive co-captain by his teammates in his first season in San Diego after playing nine seasons for the Seattle Seahawks, who won a Super Bowl after the 2013 season.

“He’s somebody that does everything that you ask of him, from the standpoint of leadership in the locker room and in the meeting room,” Chargers defensive coordinator John Pagano said. “With his physical presence inside, he’s hard to block. All I know is when you watch him go against people, they’ve got their work cut out for them, and that’s the type of presence he brings to our run defense.”

Brandon Mebane made his first career interception in his 10-year NFL career against the Raiders on Oct. 9. Ezra Shaw/Getty Images

The Chargers have not finished in the top 10 in the NFL in rushing defense since 2012, when San Diego gave up just 96.4 yards per game.

San Diego’s turnaround defending the run should not be a surprise. The Seattle Seahawks finished in the top 10 in rushing defense every year since 2012 during Mebane’s time with the team.

The Chargers will need Mebane and the rest of the team’s offensive line to bring their ‘A’ game against a Denver offense that rumbled for 190 rushing yards in a 27-9 victory over the Houston Texans last week, although the Broncos will be missing starting running back C.J. Anderson because of a knee injury.

“That’s a big pickup for them,” Denver Broncos head coach Gary Kubiak said about Mebane. “Obviously, he’s very active inside. They’re creating a lot of negative football plays because of their quickness up front, and the stunts and stuff. It will be extremely important that we can eliminate those because we had way too many of them the first time around.”

Added San Diego quarterback Philip Rivers: “I can’t say enough about him. Obviously what he’s done on the field, seeing some of the plays he makes going sideline to sideline, and what he does to opposing centers is awesome.”

Damion Square, a reserve defensive lineman who serves as Mebane’s backup, says what makes the former Cal player unique is his versatility, understanding of offenses and ability to play fast.

“I’m always waiting to see what he’s going to do next -- just watching him and trying to steal stuff from him,” Square said. “He’s a great guy, when I do go in and get my reps, to compete with and against at the same time.

“When he does something like that and you’re on the sideline, you’re like, ‘I have to do something like that or something better.’ Just to have a guy that’s pushing everyone in the room, that’s how you create a great team and a competitive atmosphere. And that’s what he does. I haven’t seen too many guys like him. He’s definitely a special talent.”

Mebane is part of an infusion of talent that has San Diego’s defense playing more consistent defensively this year.

The addition of Joey Bosa and Jatavis Brown in this year’s draft, along with cornerback Casey Hayward, safety Dwight Lowery and Mebane in free agency, improved the talent level on defense.

Along with that, players already on the roster such as outside linebackers Melvin Ingram and Kyle Emanuel and defensive lineman Corey Liuget have experienced growth in their development

The Chargers have 17 sacks this season, which is tied for ninth in the NFL. The Chargers have not finished in the top 10 in the NFL in sacks since 2010. San Diego also has forced 12 turnovers this season, which is tied for seventh in the league.