It was late on a Wednesday night two years ago when Matt Cauquil’s phone rang. “We need someone here tomorrow morning who speaks English and French,” said Yann Guerin, Paris St-Germain’s head of press. Cauquil wanted to know what the job was. PSG would not tell him anything more.

The next morning, in an office inside the Parc des Princes, the club confirmed what he had to do: interpret David Beckham’s unveiling as a PSG player, the highest-profile press conference in the history of French football. Like a bride on her wedding day, Leonardo was desperate that everything should be perfect and tested Cauquil’s immaculate English, impressing on him repeatedly how important this was and how nothing must go wrong.

Leonardo and Nasser al-Khelaifi need not have worried. As they flanked Beckham on the main table down in the ground’s auditorium, Cauquil, perched behind his own flimsy table on the edge of the stage, turned French into English and English into French, the crucial conductor of the biggest show on earth.

This is the life of the football interpreter, the background figure who is one of the great winners of the globalisation of the game. The insatiable demand for words and content, the growth of every press conference into an internet event, and the spreading foreign fan bases of every major club have all combined to make the men and women who can convert one language into another an indispensable army of modern football.

Overseeing much of this, from his office in London, is Peter Clark, the owner of Clark Football Languages (CFL) and kingpin of the football interpreting scene in Europe. Clark started CFL in 2001 and they now have over 250 interpreters, responsible for staffing many of the biggest games and teams across the world.

Sitting down for coffee with The Blizzard in west London, Clark explains how his company has carved out their position. “We are very well established in the UK in what we do,” Clark says. “Our interpreters are very well known at most clubs.”

The list of markets that CFL has cornered is a long one. “In Scotland we are the main provider,” Clark says, “in Germany we work with all the clubs that play in Europe. In Holland, we work with all the clubs that play in Europe. In France we are the main provider. In Spain, we work with Barcelona and most of the clubs playing in Europe. In Italy we are a monopoly, in Greece we are a monopoly and in Austria and Switzerland we work with all the clubs in Europe.”

Only here in Britain does CFL face much competition, in the form of Phil Dickinson’s Premier Language Solutions agency, based in Glossop in Derbyshire. 21 years before Beckham joined PSG, Dickinson interpreted the first most famous Anglo-French unveiling, when Éric Cantona signed for Manchester United. Last year, Dickinson translated the autobiography of a Manchester icon of another generation, Sergio Agüero.

Dickinson, who speaks French and Spanish, spent the 1990s mixing interpreting with other work. He tells The Blizzard how, after the friendly between England and Colombia at Wembley in 1995, he and Martin Tyler tried to coax René Higuita out for an interview after his famous scorpion kick. “Higuita was really shy and didn’t want to come out of the dressing room,” Dickinson says, “but in the end we got him and he was just sticking his head of the dressing-room door.” This sort of thing was not exactly commonplace at the time and it was five years later that Dickinson set up his company. Today, PLS works closely with Manchester United, Manchester City, Everton and Liverpool.

Most football interpreters, like most football journalists, are those who realised in their youth that they were not good enough to play professionally and so found another job to take them close to the game. Clark reached a higher level than most, playing as a teenager for the semi-professional side TSV Nordstern 05 Gauangelloch. He grew up in Heidelberg, the son of an American father who worked for Nato and a mother “as English as English could be”. 

Clark grew up translating for his parents before training at the Defense Language Institute in San Francisco. He then worked for various sports information services and moved into translation. Clark still does that work, whenever there is a high-profile English-German job that needs doing. 

Interpreting is the bread and butter of the industry, the most important skill which is the basis for everything else. There are two forms: consecutive, in which the interpreted answer follows the original one, and simultaneous, usually performed from a booth at the back of the room. Many football interpreters are qualified to work with the European Union or the UN, but there is a special skill, and a particular pleasure, to working in football.

“You can have an EU interpreter from Brussels, you stick them there for a political event and they will be like a machine,” says Clark, who supports Borussia Mönchengladbach and will only employ genuine football enthusiasts in his company. “But if you stick them next to a football manager like Harry Redknapp, they can be out of their comfort zone. There is no guarantee they’ll do a good job. If you work in football interpreting you’ve really got to know football inside out.”

Those who do interpret at press conferences love it. Patrick Kendrick is one of CFL’s rising stars, working in Italian and French – he did all the PSG translation when they were in London in March – and he described how it felt. “If I could only do interpreting work, I would,” he says, a few days after the second leg at Stamford Bridge. “There is not much like the rush of interpreting. I find that, after every job I’ve done, for an hour after I’m on a high almost as if I am drunk. And then you have a crash after that, such is the energy that you use. With simultaneous interpreting, there are studies which prove that technically the human brain should not be able to do it. To master it gives you a lot of satisfaction.”

The hardest man to interpret for, according to almost everyone spoken to for this article, is the most successful ever to graduate from this profession. José Mourinho is still known as ‘el traductor’ in Barcelona, in recognition of the job he used to do under Bobby Robson. He is famously multi-lingual and excelled in that field before he excelled as a coach. So he is always alert, examining the interpreter’s notes and is not averse to correcting them when they have mis-stepped.

Mourinho has mastered the language of every country he has worked in, showing off his grasp of Milanese slang when he started off at Internazionale in 2008. Not all players are quite as gifted as him, though, and the increasingly cosmopolitan make-up of Premier League squads has created new opportunities for these language companies. 

“Even though we started out as a football interpreting company, translating and press conferences” explains Clark, “we now do everything, the whole span, everything to do with languages across Europe, and language lessons are huge.” Both CFL and PLS teach English to many of the foreign players in England and also offer whatever other help is required. CFL used to have an interpreter at Queens Park Rangers whose job it was to translate all of Luigi De Canio’s touchline instructions, meaning that if he swore in Italian their man would have to find the right bluntness in English. 

Sometimes these responsibilities extend beyond football. Dickinson remembers translating the entrance exam for the prestigious Bolton School for Claudia Hierro, Fernando’s nine-year-old daughter. She passed.

Then, of course, there is journalism and the desire to learn about the nature of the game across the world. Take, for example, The Real Football Factories International, the cult Danny Dyer-fronted documentary series which revealed the persistence of football hooliganism – often inspired by the traditional English firm – across the world. Susie Valerio is a voice-over artist and interpreter who, owing to her Brazilian background, translates for Arsenal’s new signing Gabriel.

Valerio worked as a producer on the Brazilian episode of Dyer’s series, locating the firms – from Flamengo, Vasco, Palmeiras, Corinthians and the rest – that Dyer needed to be seen with. “I found all the hooligans online,” she told me. “Once one firm confirmed, they all confirmed. They all knew who Danny was. They follow all things hooligan in England, and as soon as I mentioned Danny they said yes.” Valerio interviewed the hooligans in Portuguese and Dyer’s voice was added afterwards. 

The real change, though, the way in which the changing face of football is creating work for these interpreters like never before, comes through the global expansion of fan bases. Every big club now cultivates support abroad and this means diversifying their websites and social media platforms, producing the material to connect with those who follow a team without attending the games. This is where the bulk of the work is now, especially with Asian languages, and it will only expand.

“The demand has increased, mainly through the advance of technology in media, in Twitter and Facebook, we never had that 10 years ago,” explains Clark, who knows where the future lies. “Now, if Borussia Dortmund sneeze in another language, we translate it. We do their website, we do their Twitter, we do their Facebook, we do their games.”

What this means is that what was once a niche industry, an exotic curiosity, has become part of the fabric of the global game in 2015. The big teams and competitions are so delocalised now – in their ownership, their management, their players and their support – that teams of interpreters are needed to make sure they can talk to each other. If your team cannot communicate with a target market you know that your rivals will.

And so like all of the football service industries – from journalism to player representation – it is now incredibly attractive. Every week Clark gets bombarded with e-mail enquiries about working for CFL and he guesses that the folder of interested youngsters on his laptop now contains 3,000 CVs.

“People love football, don’t they?” he says. “If you’re a young guy and you’ve just graduated from translation school, you love the game and you hear about someone who does this in football [rather than outside football], you’d far rather do this.”