As soon as he hears the question, Nnamdi Asomugha can’t help but light up.

The writer and director of The Knife, which premiered at the Tribeca film festival earlier this summer to impressive reviews, has just been asked about the similarities between film-making and being an athlete.

“It’s so deep. There are so many ways I can go with that question,” Asomugha tells the Guardian. “It really all depends on which career you’re talking about. Is it acting? Directing? Producing? They all have things that carry over from football. But they’re so different.”

Asomugha is uniquely placed to broach this topic. As an NFL cornerback he thrived for the Oakland Raiders – who picked him in the first round of the 2003 NFL draft, before he went on to play for the Philadelphia Eagles and the San Francisco 49ers over his 11-year career. He was voted All-Pro on four occasions, played in the Pro Bowl three times, and is widely regarded as one of the best shutdown corners of the last 25 years.

Since the end of his football career, Asomugha has pivoted to Hollywood. But this isn’t the usual story of an athlete utilizing their immense strength in action roles – see Dwayne Johnson, Jason Statham or Carl Weathers – or popping up in comedies to show their lighter side. Asomugha has appeared in, produced and now written and directed hard-hitting, socially-conscious dramas about the lives of Black Americans.

He was an executive producer on Harriet and Nanny, an actor and producer on Crown Heights and Sylvie’s Love, and a producer on The Banker. The Knife marks Asomugha’s debut as a writer and director and in just 82 minutes he expertly crafts a story of family turmoil, police brutality and racial bias.

Asomugha also stars in The Knife as Chris, the husband to Alex (Aja Naomi King) and father to Ryley (Aiden Gabrielle Price) and Kendra (Amari Alexis Price), whose lives are upended when a stranger suddenly appears in their house in the middle of the night. The family soon have to contended with the consequences of their choices, when Officer Padilla (Manny Jacinto) and Detective Carlsen (Melissa Leo) arrive on the scene and ask increasingly probing and intrusive questions over the incident.

Initially written by Mark Duplass, at first Asomugha was approached about acting in The Knife. Once he agreed to join the project, he was given free rein to change anything that wasn’t working for him about the script, to “take off with it” and make it his.

Duplass and Asomugha then set off on the Hollywood merry-go-round to try to find a director that they could attach to the movie, which would in turn help to secure financing. “In this business it can take 10 years before someone agrees to make something. Because every director has their own project they’re working on. We had conversations with people, but everyone was busy. That was when I realized it could take forever to get made.”

When asked to clarify the date Duplass approached him with the script, Asomugha can’t help but answer like he’s in the final stages of a crunch NFL game. “It was maybe the fourth quarter of ‘21,” he says.

Born in Louisiana to Nigerian parents, Asomugha moved to Los Angeles when he was three years old. He was then raised in Lawndale, on the edge of Inglewood and Hawthorne. Rather than growing up with a camera in his hand from a young age like a Steven Spielberg or JJ Abrams, Asomugha would “go outside and pretend” to be his favorite sports heroes. Mainly, Magic Johnson. “Sports was always the love of my life before anything else.”

But while Asomugha was playing basketball and football at Narbonne high school in Habor City, and then for the California Golden Bears football team at the University of California, Berkeley, he was constantly watching films. The first film he saw in a theater was Who Framed Roger Rabbit when he was six or seven years old, which he remembers being “blown away by.”

It was 1991’s Boys In The Hood, which an aunt snuck him into, that made the biggest impact. “I should never have seen it. But I remember constantly asking her, ‘Are you sure that’s not real?’ That was such a vivid memory. She told me it was just a movie. But it was what I saw growing up in LA. It just felt so real. That’s why I’ve always gravitated towards the combination of truth and spectacle in films. That’s the perfect spot for me.”

But when Asomugha retired from the NFL, he wasn’t originally sure what his next career would be. He tried an internship at a private equity firm, he worked to get his salesperson and broker’s licenses, he even ventured into broadcasting briefly. “But nothing was moving me,” Asomugha says. “I remember someone asking me, ‘What is it that you like? What do you love?’” He immediately thought of movies. “It just got me on the track of, ‘Well, I can try acting.’ I knew it was crazy and against the odds.”

What gave Asomugha hope was that he had already made it in an unlikely profession. He’d also previously appeared in commercials as a football player, during which directors and actors would repeatedly tell him, “You’re really good at this.” So Asomugha gave himself six months to see if he actually enjoyed it.

It was during this period that he realized he wanted to take a different approach to other athletes who have made it as actors. “I know my limitations. I admire people like The Rock who have done a tremendous job of coming into the business with a name and becoming very successful. But I just knew it wasn’t my personality. I wanted to be more than a celebrity trying acting. I didn’t want to rely on my past life in order to succeed. It was more about learning and seeing if I could exist. Then I would feel like I earned it.”

Asomugha initially struggled to land any roles because of his past of a football player. “I’d ask to audition for even the smallest role in something that was quality and I’d be turned away. I wouldn’t even get the audition. But I believed I could do it.” So he decided to create his own work and turned to producing to find roles that he wanted to inhabit. “That has since turned into I want to tell stories that aren’t out there.”

Taking the initiative is exactly how Asomugha became the director of The Knife, too.

At first his manager suggested that he direct the film. Then his producing partner. “I just kept hearing it. So when it came up in conversation, it just felt like if I didn’t direct it wasn’t going to get made.” Unlike most film-makers, Asomugha had never dreamed or desired to step behind the camera. But he knew that by stepping up they could make the film for a certain amount of money and move forward rather than waiting for a studio or production company’s approval.

As someone who has produced several movies, he also felt well-placed to direct. “I had an understanding of shots and lenses. There was a lot I didn’t know. Like talking to the actors. But I learned through fire. I’ve had examples of that in my life, especially through football. I know that’s where I do my best and learn the most.”

Having been the captain on every sporting team that he’s ever been on, Asomugha felt at home calling the shots. “You’re the leader. I learned in football how to lead. I was able to convert that into how I lead as a director and as a producer. It’s a lot of the same things from football. We are one unit. We’re only as good as our weakest link. Then acting is about reacting. That’s everything that playing defense is about. You’re learning body language. Responding in the moment.”

Ultimately, Asomugha is shocked by just how transferrable his sporting mentality and skills have been to movies. “I found many ways to convert the skills I used in my football position into acting and directing. It’s crazy. I never would have thought they’d intertwine so much.”

But while Asomugha is hopeful there will be many more opportunities to utilize these talents, he still doesn’t have a set plan for his second career. Instead, he’s willing to stumble in whatever direction his gut-feelings take him. “Acting will always lead the way. I definitely want to direct again. I’ve now fallen in love with it. But, you know, I stumbled into football. I wanted to play for the Lakers. Now I feel like I stumbled into movies. None of this was the path. I’m just going to allow myself to go where I’m called next.”

• The Knife will have its international premiere at the Deauville film festival in September. Asomugha can next be seen in the Apple TV+ series The Savant opposite Jessica Chastain.