The Manchester City defender’s tough training regime at a youth academy saved him from the streets, and his steely temperament should prove crucial as he steps in for Belgium’s absent captain at Euro 2016

This article is part of the Guardian’s Euro 2016 Experts’ Network, a cooperation between some of the best media organisations from the countries who have qualified for France. theguardian.com is running previews from three countries each day in the run-up to the tournament kicking off on 10 June.

He has some Kompany in him. His nickname (the new Kompany), his club (Manchester City), his position (central defender), his skills (strong, fast, technically good), his origin (a Brussels ‘ketje’ from a mixed family) and this summer he could also replace him in the national team. Let’s introduce you to Jason Denayer, a warrior trained in bare feet.

He would probably rather make a name for himself – and he may have to wait a few games after Marc Wilmots decided against starting him at Euro 2016 in central defence – but Denayer cannot deny the comparisons to his countryman. When he signed on loan for Celtic in 2014, the Scottish club proudly presented him as the “new Kompany”. It said everything about his reputation and his potential. Only time will tell if Denayer follows in Kompany’s footsteps to become one of the Premier League’s best defenders. The 20-year-old defender spent the past season on loan at Galatasaray but in the summer he returns to Manchester City and he hopes to convince Pep Guardiola of his qualities.

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Denayer is not quite as expressive as his idol just yet – he is quite shy, as well as calm and kind – but he is strong-willed and very competitive. When he was five, he was taken by his dad to Ganshoren, a local team in Brussels, but the coach rejected him because he was too young – in Belgium you cannot join a club to play organised football before the age of six. “I was so devastated that I still remember that day,” Denayer told Het Laatste Nieuws. “Rain was pouring down and I saw Junior Malanda – born in 1994 – running on the pitch. While I wasn’t allowed to. It motivated me. I was determined to join the club a year later.”

Denayer likes rapid progress; things have to move on. Aged 11 he had a trial at Anderlecht, Belgium’s biggest club. His team-mates did not pass to him, so he told his dad he had no interest in joining ‘Paars-wit’ (the purple and whites). “I want to go back to Ganshoren.” When Anderlecht knocked on his door 12 months later, he agreed to join them, although he did not last long.

A key moment came when, as a 13-year-old, he was watched by scouts at the newly founded Académie Jean-Marc Guillou. “One of my best friends was on a trial in the academy,” recalls Denayer. “He told me that they played football for four hours every day. It fascinated me.” On the last of the four trial days at the academy, he was exhausted from all the running around. Someone suggested to him to try out as a defender. It worked out well.

After the session Vincent Defour, one of the coaches, walked towards him and asked: “Are you dreaming of a professional career?” Denayer knew he would struggle to match the small, technically gifted strikers he had seen during the trials and decided to become a defender. He signed a contract for the JMG Academy and never looked back.

Guillou, the founder, was one of Arsène Wenger’s star-spotters and is credited with developing the Touré brothers, Kolo and Yaya, Gervinho, Emmanuel Eboué, Salomon Kalou and many more in his African academies. He wanted to replicate his successful concept in Tongerlo, close to Antwerp. The move met with a lot of resistance from the professional clubs. Not only were they upset that the academy snapped up some of their young talents, but prospects had to sign a contract and were withdrawn from normal competition football, playing only small-sided games among each other as they wanted to focus on technique and education in a private school.

They trained in bare feet to improve their touch. “The regime was tough and during the first few weeks I had my doubts,” recalls Denayer. “Your day started at 7am and ended at 10.30pm. In between you had 90 minutes – just before bedtime – to call your friends or family. It was playing football, studying, eat, sleep. As a 14-year-old, I could easily cope with the regime, but I still remember that there were also nine- and 10-year-old guys. Every Monday, they were constantly crying during the trip from Brussels to Tongerlo in our minivan.”

The academy saved him from the streets: drugs, criminality and other problems kids in his situation would face. His family – his dad is Belgian, his mum Congolese – had moved to the Anneessens quarter, one of the deprived areas of Brussels. He used to be on the street a lot. “You had to be careful, even when you were playing football,” says Denayer. “One silly contact could cause an explosive atmosphere. I’ve known boys who were more talented than me, but have never made it. They made other choices. That’s the danger of growing up in a tough neighbourhood.”

By the time Denayer was 18 he had developed into a strong defender. He was always blessed physically – big and strong, fast and smart – but he could also dribble and played without fear. Lierse, the club that had a partnership with the academy, wanted to tie him up as a semi-professional but the player had higher hopes. He rejected the offer and made a tour around England.

He had a trial at Liverpool, but club and player never reached an agreement. His next stop was City. “It took months for the club to take a decision – the longest period of my life,” Denayer says. “But when I signed a deal, I was super-happy. I got my chance in the EDS [elite development squad] team and trained with the first team.”

In the summer of 2014 he joined the first-team squad on their pre-season tour of the United States but played only a few minutes. “My agent told me that the Celtic manager [Ronny Deila] had watched some of the EDS games and that he was interested in signing me. I said to myself: ‘Glasgow, the city where the sun only shines one week out of a year?’ But the manager called me and convinced me to join. I was euphoric and nervous at the same time. Before we reached the dressing room during the stadium tour, my dad told me: ‘Jason, once you walk through that door, you are a professional player. And you will have to behave like one too.’”

In his first game at Celtic Park, against Dundee, he scored his first goal after just four minutes. Denayer says “the jigsaw fell into place”. He won the Scottish title, the League Cup and was elected as the PFA Young Player of the Year. His first season at the highest level was one long dream.

A young boy once made a similar start in the Belgian Jupiler Pro League. His name: Vincent Kompany.

The secrets of the other squad members

Axel Witsel

The sky is the limit for Axel Witsel. Since the beginning of this year the Zenit midfielder has been the co-owner of LindSky Aviation, a company that trains pilots and sells private jets. Currently he is the ‘Chief Relationship Officer’ but he has the ambitious plan to lead the company when he retires. “While my team-mates are playing on their PlayStation, I can read some pilot courses,” he said. “After my career I want to get my flying licence.”

Radja Nainggolan

Belgium’s gladiator, ‘Ninja’ as he is called at Roma, has his scars. Radja has always been a fighter, as a tattoo on his left leg reveals; on and off the pitch. His dad left a family of five when Radja was five and returned to Indonesia – something the midfielder would never forgive him for. Six years ago he lost his mum after a battle against cancer, with euthanasia carried out. For Radja and his twin sister, Riana, who also plays football, their mum meant everything. He has a tattoo featuring two wings up his back to his neck, a tribute to his mother. The powerful image also has her date of birth and death on it. When he was 17, he moved to Italy. He survived homesickness because he wanted to live his dream: to become a professional footballer.

Jan Vertonghen

Belgians love modesty. And, despite his reported salary of £60,000 a week, Vertonghen won a lot of sympathy in October 2015. While his team-mates were turning up in their posh cars - Witsel in a Cadillac, Kevin De Bruyne in a fancy SUV - the Tottenham defender was dropped off by his mum in a nine-year-old Toyota Corolla. He was even granted a goodbye kiss. The Corolla has a huge emotional value for the Vertonghen family. It was the last car his parents bought before his dad passed away after a lingering illness. Vertonghen doesn’t have a car in Belgium and always stays with his family when the national squad come together. In London he drives a Porsche.

Romelu Lukaku

A killer in front of goal, a rapper in the back of his mind. The Everton striker is in love with football, but also had a second passion: he adores music. He arrived at the training camp in May with a huge suitcase. He had brought his DJ decks stand, to entertain his team-mates with his rap music. Lukaku shares some of his favourite songs on Instagram too. There’s a funny video of Lukaku singing rap on request, next to Thibaut Courtois.

Jordan Lukaku

Romelu’s brother is a fast guy on the pitch, but he was also given a €2,880 fine and a 12-month driving ban for speeding and driving without a licence last summer. The judge said the left-back may go to jail if he offends again. It was the last warning sign for the younger Lukaku. The episode and the death of his best friend and Wolfsburg player Junior Malanda – after a car accident – opened his eyes. He became more professional, had an excellent season and pushed his bad image to the background.

Kristof Terreur writes for HLN.

Follow him on Twitter here.

Click here for a tactical analysis of Belgium.