New Leeds manager Javi Gracia, Wolves' Julen Lopetegui and Unai Emery at Aston Villa are the other Premier League bosses to have played for the club and, while the only one to manage the La Liga side was West Ham's Scottish boss David Moyes, the footballing wisdom exuded at their Anoeta home is contagious.

"They become fully impregnated with this culture," explains Andoni Iraola, not the Rayo Vallecano boss - although he too was born in Gipuzkoa - but a Real Sociedad director.

"What we try to do is try to understand sport as something that not only has to be played, but something that has to be developed.

"People are not only interested in the end result but what the game is about, what the whole thing is about."

On Thursday, Real Sociedad will look to take that philosophy and leave a more direct mark on the continent when they visit Jose Mourinho's Roma in the Europa League last-16 first leg, having already won at Manchester United earlier in the competition.

La Real's growing influence on European football since returning to La Liga 13 years ago has made them a name that stretches far beyond San Sebastian, a city of just 187,000 people, and they are on course for the Champions League next season.

Run by more than 14,000 socios, who helped keep the club afloat when they were relegated, Iraola says Real Sociedad "belongs to everybody" and their values remain entwined with the community.

Developing local talent is key for the Basque side to compete with Europe's biggest clubs and 80% of youngsters in La Real's famed Zubieta academy were born in Gipuzkoa - 16 of the current first-team squad are also homegrown.

"The work done here at Zubieta is something from the very first day we feel very well supported by everybody," says 25-year-old Spain international Mikel Oyarzabal, currently the most-prized asset to emerge from La Real's youth system.

"You receive all kinds of help from different sectors, not only sport - they can give you the tools required to play football, but also the tools you need for your daily life. It is a wonderful setting, a wonderful environment."

Oyarzabal scored the winner in the Copa del Rey final as La Real claimed their first trophy in 34 years in 2021 under the guidance of head coach Imanol Alguacil, who also came through the academy, played for the first team and began his coaching career with the club's youth teams.

"It was only a few years ago the club were having some very difficult years," adds Oyarzabal. "It is a process. The beautiful things are being seen now but it was all to do with the work done years ago."

La Real's line of succession

For sporting director Roberto Olabe, that process involves a commitment to improving the squad every July. He talks of "fostering a line of succession" for the short, medium and long term - when a weakness is identified, Olabe moves to fill that position.

It is often mutually beneficial for club and player - Arsenal captain Martin Odegaard reignited his stalling wonderkid status in the fertile surroundings of the Reale Arena, while Newcastle forward Alexander Isak would offer a similarly glowing review.

At the other end of the spectrum, David Silva, Nacho Monreal and Asier Illarramendi have previously arrived to generate experience.

"Imagine what it means to train alongside these every day?" says Olabe.

The former goalkeeper adds: "In a development process you need to project things, but you have no guarantees a 13-year-old winger is going to become the right winger years later.

"We are optimistic and think he could be - he is only 13, he is not yet a football player but a child - and we are going to train him so he can become the best kind of football player so he could eventually join the first team.

"When we detect a weakness in this line of succession based on positions or profiles, that's when we go outside and we will then look into the profile we need.

"We are looking for players who will make it possible to play at different levels, passing the ball, being more stable, dominating spaces, very good in transitions - we want to address what is currently demanded by elite football. You have to look for the people you don't have at home."

Real Sociedad beat Manchester United 1-0 at Old Trafford in the Europa League group stage

Beat Roma over two legs and La Real will reach a European quarter-final for the first time since 1989, something that will only enhance their global profile, but Olabe's focus is on the bigger picture - football is "very reactive", he stresses.

And underpinning all La Real do is patience, first in only recruiting youngsters from the age of 12 - instead supplying grassroots teams in the province the tools to develop their own talent until that time - and then in moulding them into first-team players.

"We are permanently learning," says Olabe. "If you consider long-term development, patience doesn't mean that you have to wait. By being patient you have to search, patience means you have to persevere. It means you have to see where your limits and thresholds are.

"There are many places where people are spending far too much money on processes we break up ourselves. At 14, 15, 18, 20 I know of no architects or musicians that are outstanding, so it is very difficult to discover a football player at that age too.

"A football player needs time. This is a very aggressive world and you are highly exposed to public opinion, so they need to have a significant emotional foundation.

"Patience doesn't only have to do with crossing your arms to see what is going to happen, patience has to do with your commitment and your responsibility with regard to having development programmes for young players and training them based on professional ethics and to deal with the world of professional football."

It is that investment in their own sons and daughters - La Real's women's side were runners-up in the top flight last season - the people of Gipuzkoa expect.

"The Zubieta brand doesn't have to do with how much money we make or how many titles we win," says Olabe.

"In this club, one of the beautiful things is everybody understands the level of demand in the elite teams is enormous, but everybody is willing to open doors for these people because young people offer an opportunity."