When the Cardinals drafted do-it-all defender Isaiah Simmons with the No.8 overall pick in this year’s NFL draft, General Manager Steve Keim said the franchise had found its “Eraser.”

“You watch him on tape,” Keim said at the time, “and you see him play the deep middle, the deep half. You see him play in the box, you see him blitz and rush the passer. … We call that kind of player an ‘eraser’ in this league.”

Thanks to signing their “X-Man” a month earlier, the Cardinals already found their difference-maker at weakside inside linebacker in free-agent De’Vondre Campbell. According to head coach Kliff Kingsbury, Campbell was the team’s top-rated linebacker on the market and others in and around the organization have suggested Campbell might have been the club’s biggest free-agent addition catch overall.

“He’s been kind of an X factor so far and I’m hoping as the season goes on, he get gets even more comfortable in our system and he continues to improve,” Kingsbury said this week of Campbell, who had a monster game in Arizona’s home-opening victory over Washington with 10 tackles, two of them for losses, and two pass breakups.

Campbell joined safeties Budda Baker (2019) and Adrian Wilson (2012) as the only Cardinals defenders in the last nine seasons to post those type of numbers in a single game. It was Campbell’s seventh career outing with 10 or more tackles, five of which have now come in his last 15 games dating back to last season.

Asked where Campbell has made the biggest impact, Kingsbury responded with a question of his own, saying, “Really, where hasn’t he?”

“You watch where he was at and he was all over the field,” Kingsbury continued. “Whether it’s the run game or the pass breakups, I mean, he was everywhere. He’s got great length, he’s got great instincts and he’s a matchup with any tight end in the league and we’ve got some great ones we play against.”

Campbell’s 17 total tackles rank second on the team behind Baker’s 18 and he’s on pace for a career-high 136 after finishing with a personal-best 129 last season for the Falcons. He will be a defensive player to watch this Sunday when the Cardinals (2-0) host the Lions (0-2) at State Farm Stadium, primarily because he has built a reputation for shutting down opposing team’s tight ends.

If you follow the Cardinals at all, you’re aware they’ve been negligent in that department. No team in the league allowed more receiving yards (1,173) or touchdowns (16) to tight ends a year ago than the Cardinals. Detroit’s T.J. Hockenson started the trend by torching Arizona in the season-opener a year ago, catching six passes for 131 yards and a touchdown in a 27-27 tie.

Washington tight end Logan Thomas, the former one-time Cardinals quarterback, caught four passes for 26 yards on Sunday. Campbell, though, didn’t allow any of them and he also broke up a couple of throws targeted to Thomas.

“I don’t think he had a ball caught on him,” outside linebacker Devon Kennard said.

He didn’t. And whether he’s in coverage assignments against Hockenson or the Lions’ other two tight ends, Jesse James or Hunter Bryant, Campbell knows what he must do. He bragged about it this offseason.

“I still honestly believe I can cover any tight end in this league,” he said. “It’s professional football, so of course this is the best of the best, but I’m very confident in my abilities.”

Eventually, that job will someday fall to Simmons, the former Clemson star who last season won the Dick Butkus Award, recognizing him as the best linebacker in the nation. Simmons’ defensive snaps from Week 1 to Week 2 were cut in half, however, and his rookie season for now appears to be more of a watch-and-learn scenario behind Campbell.

Initially, there was some hope that Simmons could pick up where he left off and form some type of Three Amigos situation at inside linebacker with Campbell and strong-side stalwart Jordan Hicks. Because of the COVID-19 pandemic and the NFL’s decision to cancel preseason games, that chance never materialized.

MORE: Arizona Cardinals vs. Detroit Lions picks, predictions: Who wins Week 3 NFL game?

In some ways, however, it seems the Cardinals always knew that Campbell was going to be their “X Factor” and the “Eraser” would likely have to play sparingly and mostly sit and watch.

“He’s doing what we thought he could do,” Kingsbury said of Campbell. “He was our top-rated linebacker in free agency and we were fortunate that we were able to get him for this season. We felt like he was a great guy. He and Jordan Hicks are great guys for Isaiah to learn behind and figure things out as he kind of builds not having an offseason but can learn throughout the season.

“We feel like it’s really going to help him as well.”

Campbell’s arrival did more than just impact Simmons’ rookie season. It also forced a position change for the Cardinals’ popular playmaker Dennis Gardeck, who was asked to move from inside linebacker to outside linebacker and focus once again mostly on playing special teams, where he was named a team captain.

Technically, Campbell is under contract for only the 2020 season, but he’s already vastly improved a position that needed another major shot in the arm.

“It’s a spot we’ve gotten better at, obviously,” defensive coordinator Vance Joseph said. “Starting with Campbell, a guy who’d played in big games. He’s a tall, long inside backer. That’s very rare. He’s a rusher, he’s a cover guy, he’s also tough and he’s smart. Obviously drafting Isaiah and adding him to that mix, it’s a long, tall room which you need in this league now because tight ends are primary targets for most teams now.

“You have to have guys who can run and cover tight ends and also be strong enough not to be pushed off by tight ends and to play in the A, B and C gap in the run game. Those guys are so rare – to have guys who can cover on first, second and third down and also fit the run game on first, second and third down.”

Have an opinion on the Arizona Cardinals? Reach McManaman at [email protected] and follow him on Twitter @azbobbymac. Listen to him live on Fox Sports 910-AM every Tuesday afternoon at 3:30 on Calling All Sports with Roc and Manuch and every Wednesday night from 7-9 on The Freaks with Kenny and Crash.

News and information you can trust. Start your online subscription.