SANTA CLARA >> It was Deommodore Lenoir’s 12th birthday, and his youth football teammates were scheming a preadolescent right of passage.

Traveon Anderson, still one of Lenoir’s closest friends, recalled a “boys will be boys” plan that would result in Lenoir getting hit on the arm a dozen times. One for each year.

“At that age, everyone wants to get their licks in,” Anderson said in a recent phone interview. “We tried to catch him, but he ran and jumped over a gate and was gone. He was so fast it was like, ‘Man, forget it. We ain’t catching him.’”

Speed. Athleticism. Common sense. Three qualities among many that would eventually catapult Lenoir to high school stardom in South Los Angeles, the University of Oregon and eventually to the 49ers.

In a mostly forgettable 6-8 season, Lenoir is considered part of the solution in a season rife with problems by virtue of a five-year contract extension worth up to $92 million signed on Nov. 13. At 5-foot-10 and 200 pounds, Lenoir isn’t the long, lean prototype cornerback that gets snapped up in the first round.

When Lenoir was drafted in the fifth round in 2021 at No. 172 overall, 22 cornerbacks went before him — and that includes Ambry Thomas, whom the 49ers took in the third round at No. 102.

Yet Lenoir, 25, is the rare corner who can be sticky in coverage on the outside and seamlessly move inside to hunt with linemen, linebackers and safeties with the relentlessness befitting his nickname of “Hyena.” According to Pro Football Reference, Lenoir has played 491 snaps in the slot, 126 outside and with 51 snaps coming at or near the line of scrimmage.

“I’d rather just say I’m a football player,” Lenoir said in a recent exclusive interview. “I can fit in wherever is needed.”

Whatever changes the 49ers make this offseason, Lenoir is a foundational piece. While Lenoir’s comfort zone on the 49ers defense is just about anywhere they line him up, coach Kyle Shanahan threw Lenoir a curveball going into their Week 14 game against the Chicago Bears.

Aggressive and tenacious by nature on the field, Lenoir off the field is more quiet and reserved. Which is why a FaceTime message from Shanahan the Friday before the game was more daunting than facing any of the Bears receivers.

“He told me we’ve got one of the grittiest games coming up and when I think of the grittiest players, you’re one of them,” Lenoir said. “So I want you to say something to the team. In my head, I’m already saying, ‘No.’ But I can’t tell the head man that. I can’t tell him no.”

Lenoir spoke from the heart the night before the game and got through it.

Middle linebacker Fred Warner has addressed the team fairly regularly and describes the feeling of everyone looking at the speaker as intimidating.

“But Demo, man, he’s earned that right. It doesn’t matter what he was going to say, because everyone has so much respect for who he is and how he plays the game,” Warner said.

Lenoir has two interceptions, eight pass breakups, a forced fumble and 72 tackles — including two for losses. With Nick Bosa (hip, oblique) and Warner (ankle) battling injuries, the case can be made Lenoir has been the 49ers’ best defensive player.

The ninth of 12 children of a construction worker and a work-at-home mother (his father also has nine children from a previous relationship), Lenoir was raised to respect education and to strive to be his best.

By the time he got to Salesian High-Los Angeles, Lenoir quickly became one of the state’s top talents. As a senior, he carried the ball 108 times for 1,172 yards and 17 touchdowns, had 663 yards receiving and seven touchdowns and passed for 595 yards as a quarterback. He also played defense, made 52 tackles with an interception and two forced fumbles.

His dedication level was clear to Anderson after a Madden video game marathon that didn’t end until 3 a.m.

“We had a beach football camp at 6 the next morning,” Anderson said. “Demo was the only one who went. And then he went to another practice after that.”

One of his coaches at Salesian, Devah Thomas, described Lenoir as a product of his family and environment.

“He’s always been humble and hard working, an overachiever,” Thomas said. “He loves proving people wrong and he’s determined to be great.”

Thomas, now the head coach at St. Pius X St. Matthias Academy, is close friends with Richard Sherman, the former Seahawks and 49ers cornerback who works as an analyst for Prime Network.

“Devah was like, ‘This is my guy. This is the one. This is the one that’s going to make it big,’” Sherman said at the 49ers’ Thursday night loss to the L.A. Rams. “I went to Salesian to speak to the team and talked with Deommodore. He was inquisitive, asking all the right questions, and had a lot of hunger. The same things that make him special today.”

At Oregon, Lenoir started his final 34 games, including seven as a senior in a COVID-19-shortened season and was named second-team All-Pac-12.

Going from a full house in buzzy Los Angeles to the solitude of Oregon was initially a culture shock, something Anderson realized on his first visit to Lenoir’s dorm.

“L.A. is such a big, fast, noisy city,” Anderson said. “Helicopters, sirens, cars all day, airplanes all day. When you go to Oregon, it’s peaceful. It threw me for a loop.”

Lenoir considered the move vital to his maturity as well as his future.

“My mom didn’t want me around all the gangs and stuff, and going to Oregon taught me how to be a man because I had to take care of myself,” Lenoir said.

Lenoir has added responsibility in the form of a 3-year-old son named Titan, and has had his perspective shaped by a 10-year-old sister with Down syndrome named Cleyan.

“She’s a big inspiration,” Lenoir said. “It’s made me more protective, you might say.”

Hopeful of being a Day 2 selection in the NFL draft, Lenoir’s draft party turned into disappointment when it lasted into Day 3. (Coincidentally, Sherman was also a fifth-round pick who left Los Angeles to play at Stanford.)

Anderson said he and Lenoir reminisced about the snub “when he signed the 92,” a reference to his $92 million extension.

“He cried in my arms and said, ‘What if I don’t get drafted? What am I going to do now?’” Anderson said. “I told him don’t think about it, it’s all going to play out in your favor.”

While Lenoir ran from his 12-year-old birthday pummeling and was a reluctant team speaker, he plays with an edge on the field and won’t back down from a challenge such as playing both outside and inside.

“I look at it like I’m just different,” Lenoir said. “I’d rather be in the hard situation every time and never take the easy way out. If I’m going to play two positions, then I’m going to do it at a high level.”

Feisty and combative on the field, Sherman describes Lenoir’s “dog” mentality in canine terms.

“You never have to tell Deommodore to sic ’em because that’s just how he is,” Sherman said. He’s going to give you everything he’s got and you’re going to have to pull him off the field. I love that about him.”

Lenoir is a film junkie who studies cornerbacks past (Sherman, Darrelle Revis, Champ Bailey) and present (Patrick Surtain Jr., Treyvon Diggs, Stephon Gilmore). When Anderson and some friends visited recently before the 49ers played Seattle, they got a first-hand look at how Lenoir prepares.

“We’re all vibing, chopping it up, having a good time, and he’s on the couch with his head in his iPad,” Anderson said. “He loves football. I think he’d play for free.”