BARCELONA, Spain — Even in dark Gucci sunglasses, Héctor Bellerín couldn’t walk the few blocks from his apartment to the parking garage where he kept his battery-powered Cupra Born without causing a scene. Most of the swarming fans held their composure; one young woman trembled as she asked the professional soccer player for a picture. The World Cup was a month away — the first game is on Sunday in Qatar — and although he won’t be competing this year, it didn’t matter. Being a soccer player in Barcelona is like being a Kardashian in Calabasas, Calif., or anywhere else.

“I pay them to do that,” he said with a smirk.

Mr. Bellerín had recently returned to F.C. Barcelona after more than a decade as a defender for the London club Arsenal. When he was 16, he left Spain to compete in the Premier League; he barely spoke English at the time.

Now 27, he’d come back to La Liga as a zoomer’s David Beckham: a world-famous athlete with a cockney accent, a rock-star mullet and a lucrative one-year deal with Barcelona. (Arsenal let Mr. Bellerín out of his contract with them at 11:58 p.m. on Sept. 1; the summer transfer window closed at midnight. “In a moment, your whole life changes,” he said of his move.)

In addition to having impressive stats — he has 321 games and seven trophies on his résumé — Mr. Bellerín is incredibly stylish, a reformed consumerist with an appreciation for Craig Green and Raf Simons; the facial symmetry of a movie star; and cool designer friends like Supriya Lele and KidSuper’s Colm Dillane.

Mr. Bellerín has been featured in the British editions of Vogue, GQ and Esquire, and was recently on the cover of GQ Spain as one of 2022’s men of the year. He’s been called “the world’s best dressed footballer” (Highsnobiety), “the edgiest footballer in the game” (Mr Porter) and “the ultimate pioneer of the football-fashion crossover” (i-D). He even managed to wear a transparent PVC trench coat by Maison Margiela — which he paired with a Prada bucket hat at Christopher Raeburn’s fall 2019 show — without looking like a flasher.

“Clothes don’t scare him the way they seem to scare a lot of dudes,” Jonah Weiner, a founder of the style newsletter Blackbird Spyplane, said in an email. “He seeks out small labels doing interesting stuff off the radar, rummages through flea markets for gems, goes down eBay rabbit holes, and then he takes all the above and figures out how to put it together. You don’t dig in that way if you just want a cheat code to looking ‘stylish’ — you dig if you really regard clothes as a form of self-expression and self-discovery.”

In the spring of 2019, Virgil Abloh, then the men’s artistic director at Louis Vuitton, hired Mr. Bellerín, an Arsenal fullback at the time and a member of the Spanish national team, to model a pair of bright pink shorts and a matching snakeskin hoodie at Paris Fashion Week. He was in Greece when he received the call, recovering from a torn anterior cruciate ligament, which kept him sidelined for 31 games.

As Mr. Bellerín waited backstage for his runway debut, 22nd in line, his heart raced, he said. The adrenaline was reassuring: It gets triggered every time he steps onto the field with his teammates. But more than just providing the athlete with a new challenge to conquer, Mr. Abloh, who died of a rare cancer last year at the age of 41, offered a road map.“Virgil inspired our generation,” Mr. Bellerín said about the trained architect who started his fashion career as a Fendi intern. “He showed us that it doesn’t matter what industry you’re in — if you have the chance to do what you love, you grab it with both hands.” Mr. Bellerín summoned that energy the following year, when, in the winter of 2020, he set out on a long journey to create a clothing line of his own.

‘I’m allowed to love other things too’

On a gray October afternoon, in the dining room of his apartment in Barcelona’s wealthy Dreta de l’Eixample neighborhood, Mr. Bellerín was flipping through his vinyl records — a mix of Amy Winehouse, the Spanish singer Manolo García and the Australian funk band Hiatus Kaiyote. His chef was in the kitchen experimenting with new plant-based recipes.

In the adjacent living room, his rescue cat, Hanky, lolled in a leather-and-steel chair from Marcel Breuer’s Bauhaus era. Elsewhere, there were monographs dedicated to the work of the fashion designer Kenzo Takada and the photographs of Paul Outerbridge and Andy Warhol. (Last year, Mr. Bellerín, a point-and-shoot hobbyist, helped curate an exhibition of pictures by Syrian children living in Jordan’s Zaatari refugee camp.)

“As humans, we’re always putting everything in boxes,” said Mr. Bellerín, who, having just moved in, was surrounded by them. “Fashion is probably in a box marked ‘feminine.’” His friends and teammates have had opinions about his more adventurous outfits, but, of course, the same people making jokes eventually started asking for advice. “They laughed at first, then they were cool with it,” he said. “Now they want to be a part of it.”

Growing up, if he wasn’t in school or playing with his older sister, Gisela, Mr. Bellerín was hemming trousers with his mother, Matilde, a pattern cutter, or accompanying her to his grandmother’s small garment factory on the outskirts of Barcelona, where he swept the floor in exchange for candy and spare change. When his father, Jose, a retired language teacher, emphasized the importance of an education, Mr. Bellerín responded, “I want to be a football player. Nothing else.”

At 8, Mr. Bellerín enrolled at Barça Escola, a soccer training academy for children. He devoted his teenage years to the sport. And while taking online marketing classes from the University of Pennsylvania, the expectation was that he should be “thinking of football 24/7,” he said.

Even the decisions he has made in his private life have been scrutinized by fans. When, for example, he shifted to a vegan diet in 2016, fans were concerned that it might negatively affect his performance. Some have called his fashion pursuits a distraction — “as if I’m training 12 hours a day,” he said. (In reality, he spends closer to six hours daily on his soccer-related regimen.) “I love what I do more than anything,” he said. “But I’m allowed to love other things too.”

“It’s very important for us to invest in some solid projects while we’re still playing football,” said Tiémoué Bakayoko, a midfielder for A.C. Milan and a style star in his own right who, in 2020, invested in the French fashion brand Études. “It gives us way more experience and more confidence and keeps our feet on the ground and prepares us for a future off the pitch.”

To expand his own portfolio beyond a sport in which the retirement age rarely surpasses 40, Mr. Bellerín has participated in several fashion collaborations: suits with the Los Angeles streetwear line 424 for the men’s and women’s Arsenal teams; apparel and kits for the EA Sports video game FIFA 21; and, for H&M, a sustainable collection of earth-tone basics, including convertible pants with a matching gray anorak and a boxy beige cotton blazer.

Last year, he joined a jury of fashion experts who chose Priya Ahluwalia, founder of the sustainable label Ahluwalia, as the winner of the British Fashion Council’s BFC/GQ Designer Fashion Fund. Caroline Rush, chief executive of the BFC, said in an email, “Héctor’s interest in young talent, style and fashion’s role in identity demonstrated that he was there for more than having his picture taken.”

As his Arsenal star began to rise, the specter of its inevitable fall nagged at him. Especially after rupturing his A.C.L., Mr. Bellerín “realized that it was time to start doing something for myself,” he said. Like many of his generation, he’d also been looking for ways to minimize his carbon footprint; and yet he couldn’t shake the urge to keep buying new clothes. “All the fashion that’s responsible, a lot of times it’s also pretty boring,” he said. “I wanted to make things that last a long time, but that are also beautiful.”

It takes about 10 minutes to drive from Mr. Bellerín’s home to his studio in Barcelona’s rapidly gentrifying El Poblenou neighborhood. Formerly the center of the city’s textile industry, the area has become a destination for hotels with jute rugs and Detroit-style pizzas. The smell of cigarettes wafted through the industrial loft he shares with Horacio González-Alemán, his friend and business partner, which was mostly empty except for a few couches, some obscure design books and a Galaxian arcade machine.

In a corner of the room, Mr. Bellerín, who’d changed out of his gray jeans and white tank top to assume the role of fit model, was pulling a lightweight parka over his head. Tattoos covered his body; the most recent, a clown on his stomach, was done by his girlfriend, Elena, a tattoo artist and social worker he met last year while on loan to Real Betis in Seville, Spain.

The first batch of samples for his clothing brand was ready for review. Mr. González-Alemán, who previously worked in retail and public relations, nodded approvingly as the brand’s designers, Israel Frutos and Quim Barriach, the founders of the creative agency India Juliett, demonstrated the jacket’s features. “It’s modular,” said Mr. González-Alemán, 31. “You can remove the sleeves, the pockets and the hood.” Later, he added, “Maybe we won’t even stitch the label on. We’ll just give it to you with the garment, then you can do whatever you want.”

Impracticality aside, the sentiment reflects Mr. Bellerín’s outlook on fashion — as a way to communicate more than clout. Or as Mr. Bakayoko put it, “His sense of style doesn’t only orbit big logos.” Similarly, Mr. Weiner admired that Mr. Bellerín doesn’t “go on autopilot and dress straight out of a look book, or let a stylist tell him who he is.” (Mr. Bellerín doesn’t use a stylist at all.)

There was much work left to do before the introduction of the clothing to the public, scheduled for February, but Mr. Bellerín and Mr. González-Alemán, who had been exchanging ideas for nearly two years, were hopeful. The space was littered with mission statements about the brand’s identity (“no greenwash marketing”; “no minimal sans serif”) and mood boards that paid homage to Spanish techniques and traditions (the texture of Catalan jarapas, a thicker fabric typically used to make rugs and bedspreads; the cropped cut of a bullfighter’s ceremonial garb).

Their next task was to confirm the brand’s name, although the team wasn’t ready to announce it. They’d been operating under the alias G.E. as they navigated a trademark and copyright dispute.

Next, he tried on a prototype for cargo pants with vents behind the knees and a built-in system of cords that could alter the shape and length of the garment. In a different pair of trousers, they might offer shoelaces as a styling alternative. “It’s all about generating a special relationship with the piece,” Mr. González-Alemán said. “Not just the full-on consumerism of buying a thing, opening the package and putting it on.”

Everything in the collection will be made almost entirely from upcycled fabrics or recycled fibers, Mr. Bellerín said. “If it needs to be waterproof,” he offered as an example, “what’s it going to be made of? We know that every time we wash polyester, up to 4,000 microplastics run into the ocean, so we need a better way.” To keep them on track, they’d consulted with The Bear Scouts, a Netherlands-based company that connects fashion brands with factories using sustainable practices.

When the clothes are finished — Mr. Bellerín said they’re expecting to start with a collection of about 25 gender-neutral garments, followed by a line of accessories, luggage, pet gear, footwear, furniture, glass decanters and ceramic vessels — they’ll be sold direct to consumer, at least at first, for $30 to $1,000. “That’s the plan anyway,” Mr. Bellerín said. “Who knows. A month ago, I thought I’d be in London for another year.”

Back to ‘the office’

Two days later, Barcelona was competing against Celta de Vigo at a home game. Pedri González, a 19-year-old midfielder, scored a first-half goal to move the team back to the top of La Liga, bringing a stadium of nearly 100,000 soccer fans to an ecstatic boil. Mr. Bellerín, who was out for a few games with a muscle injury, applauded his team from the stands, his face partly obscured by a black Raf Simons ball cap with an embroidered Atari logo.

A few seats behind him, a teenage girl had spent the first 45 minutes of the match glued to her phone. She stopped scrolling at halftime just long enough to let an older couple exit the row. When she saw Mr. Bellerín, she gasped.

“Before, if you were a footballer, that’s the only thing you could be,” Mr. Bellerín said. “But sports aren’t just sports anymore. Clothes aren’t just clothes anymore,” he added. “Now, everything is everything.”