A great way to understand how it is that Villarreal — a soccer team from a town of only 50,000 souls, playing in a stadium that can hold a little less than half of them — finds itself in the semifinals of the Champions League is to consider the cleaning products aisle of Spain’s leading supermarket.

The supermarket, Mercadona, and the soccer club are corporate cousins. Fernando Roig, Villarreal’s president and benefactor, has a minority stake in Mercadona, Spain’s largest retail chain, but it is his brother, Juan, the majority shareholder, who is credited with turning the latter into a staple case study for business schools around the world.

Central to that approach is the idea that the customers are ultimately in charge. They are the ones, after all, who determine what their stores should stock. To ensure the company is meeting their needs, Mercadona, every so often, invites a selection of its most reliable customers to take part in a testing laboratory.

These are held at 10 stores around Spain, and each is devoted to a particular strand of the business: pet care, for example, or snacks or personal hygiene. Customers are asked not only to offer feedback on various products — the packaging, the pricing, the taste, the smell — but to advise Mercadona’s staff on how they use them.

That was how Mercadona discovered that while a lot of people were buying white wine vinegar as a condiment, they were also using it as a stain remover. “So they created a cleaning product made with vinegar,” Miguel Blanco, a business economics professor at King Juan Carlos University, once told a business journal from the Wharton School of the University of Pennsylvania. Mercadona, like Villarreal, understands that the appeal of a product depends on how it is used.

Villarreal does not, at first glance, follow the blueprint laid down by the handful of teams from outside the exclusive cabal of fabulously wealthy clubs who have gate-crashed the Champions League semifinals in recent years.

Monaco in 2017 and Ajax in 2019 felt a little like glimpses into soccer’s near future. It was in Monaco’s run past Manchester City and Borussia Dortmund that Kylian Mbappé, Bernardo Silva and Fabinho first pierced the sport’s broader consciousness. Ajax’s defeats of Real Madrid and Juventus on its way to the semifinals two years later helped turn Frenkie de Jong and Matthijs de Ligt into stars.

RB Leipzig, which made the final four in that strange, ghostly pandemic tournament in 2020, seemed like a team from the cutting edge, too. It featured the likes of Dayot Upamecano and Christopher Nkunku, and was guided by Julian Nagelsmann, the standard-bearer for coaching’s first post-Pep Guardiola generation.

Villarreal, on the other hand, does not feel like a vision of what is to come. The core of Unai Emery’s team is homegrown, with the rise of Gerard Moreno, Yeremi Pino, Alfonso Pedraza and, in particular, Pau Torres testament to the outstanding work of the club’s widely admired academy.

Apart from Pino, 19, though, none are especially young, not in soccer terms. Even Torres, the club’s locally sourced jewel, is 25, meaning he is unlikely to inspire the sort of feeding frenzy among the transfer market’s apex predators that de Ligt generated in 2019.

Instead, around that cadre of graduates, Villarreal gives the impression of being something of a Premier League vintage store, its team stocked with faces vaguely familiar to cursory followers of English soccer. There is Vicente Iborra, a 34-year-old midfielder who struggled to make an impact at Leicester City, and Pervis Estupiñán, the young Ecuadorean left back who noodled around the great Watford loan factory for a while.

Étienne Capoue, 33, spent six years at Vicarage Road, establishing himself as a rare constant on a Watford team defined by permanent change. Alberto Moreno was released on a free transfer by Liverpool. Francis Coquelin first emerged at Arsenal. Dani Parejo had a short spell at Queens Park Rangers. Arnaut Danjuma had flickered and sputtered at Bournemouth.

And then there is the Tottenham contingent: Juan Foyth, a defender who had lost his way; Serge Aurier, ditto; and Giovani Lo Celso, an extravagantly gifted midfielder who found himself out in the cold upon Antonio Conte’s arrival as manager at Spurs late last year.

Even Emery, of course, returned to Spain after being given the somewhat daunting task of replacing Arsène Wenger at Arsenal. His team at Villarreal, the one that eliminated Bayern Munich in the quarterfinals, the one that blocks Liverpool’s path to a third Champions League final in five years, has been constructed on the Premier League’s waifs and strays.

Those familiar with Villarreal’s strategy say that is not a deliberate policy. Miguel Ángel Tena, the club’s sporting director, and Fernando Roig Negueroles, its chief executive — and the son of the president — have not set out to sift through those cast aside by the Premier League’s wanton, wasteful consumerism.

There has, instead, been a degree of opportunism. When, halfway through last season, Emery needed a physically imposing, technically adroit central midfielder, he remembered being impressed by Capoue while he was in England. Capoue, who has admitted that he does not watch soccer, did not even know where Villarreal was when the offer came; he was just touched by Emery’s faith in him.

Danjuma was another signing recommended by the manager: Villarreal’s analysts had never watched him when Emery suggested, in the aftermath of Villarreal’s winning the Europa League last season, that the team should pay $20 million or so for a player who had just been relegated with Bournemouth. The club, though, paid the fee. Villarreal now believes Danjuma, its breakout star, could one day fetch $100 million.

Others have benefited from the club’s eidetic memory. Villarreal has long nurtured connections in South America in general and in Argentina in particular: When it last reached a Champions League semifinal, in 2006, it was with a team stocked with Boca Juniors alumni. Its scouting network picked out Foyth and Lo Celso long ago.

Villarreal could not compete with the money on offer from England — or Paris St.-Germain, in Lo Celso’s case — when they first came to Europe, but the club knows well enough that soccer can always bring a second chance, particularly given how quickly English clubs, in particular, discard players.

It is that insight that has allowed Emery not only to deliver the first major honor in Villarreal’s history — last year’s Europa League — but to sweep the team to within 180 minutes of the biggest game of them all: the knowledge that a product can have an alternative purpose, a more significant role, than the one stated on the packaging.

And it is that approach that, while it may not make Villarreal as compelling or as exciting as Monaco or Ajax, perhaps it makes its story a little more imitable, a little more inspiring in an age dominated both by the superclubs and increasingly by the financial might of the Premier League.

Monaco’s success was built, in large part, on the unparalleled eye for talent of its chief scout, Luis Campos. Ajax’s was a tribute to the club’s unmatched gift for nurturing and fostering promise. But both contained trace elements of lightning strikes, too: difficult — if not impossible — to repeat or replicate.

Villarreal, though, offers a template that might be followed, a vision for how clubs without the finances of the Premier League or the weight of the giants of continental Europe might be able to thrive. It demonstrates that it is possible to grow strong on the scraps from the feast, to thrive in soccer’s increasingly Anglocentric ecosystem, by remembering that the appeal of a product depends on its use.