Cesar Azpilicueta might seem to be the epitome of calm but there must be a degree of devilment to the man. Quietly, in his six years at Chelsea, his consistent excellence has made him one of the world's leading defenders.

But he was born and bred in Pamplona, the home of the San Fermin festival which features the running of the bulls through the streets. He has never participated, he says — 'only watched' — but something of the daredevil must have rubbed off on him.

For the Chelsea captain is an enthusiastic advocate of what has become known as Sarri-ball, manager Maurizio Sarri's high-risk football which places defenders in constant danger, because of the high defensive line they play.

Cesar Azpilicueta told Sportsmail that he prefers to defend as high as possible up the pitch

The defender has continued to perform consistently in different positions and formations

Five wins from five in the Premier League tell their own story. The former Napoli coach has made an impact. It will be put to the test against West Ham on Sunday.

The more cautious approaches of Jose Mourinho and Antonio Conte garnered Premier League titles, FA Cups and League Cups. So judgment needs to be withheld for now on Sarri, but certainly he seems to have the players onside.

'I prefer to defend as far as possible up the pitch,' says Azpilicueta, who was a central defender as part of Conte's back three, a left-back when he first arrived at Chelsea and is now right-back.

'It's different and you can see we press very high, the defensive line is very high but that's what we want. We want to be dominant in the game and recover the ball as quick as possible and enjoy the ball when we have it.'

Azpilicueta passed exams to study at university and started his business studies course

Azpilicueta admits that Maurizio Sarri's managerial style is 'different' but says he is adapting

CESAR AZPILICUETA'S CHELSEA RECORD 2012/13: 48 appearances 2013/14: 44 appearances 2014/15: 40 appearances 2015/16: 49 appearances 2016/17: 47 appearances 2017/18: 52 appearances 2018/19: Seven appearances Total: 287 appearances Honours: Premier League: 2014/15, 2016/17 FA Cup: 2018 Europa League: 2013 League Cup: 2015 Advertisement

Azpilicueta's reasoning is that the high line keeps the opposition strikers far from the Chelsea penalty area.

'You have the striker where you want him, as far as possible from the goal. These days, even when you are in the box you cannot feel safe because the quality the strikers have. It's more complicated to defend there.'

Unlike most other coaches, who have been mentored by great managers and brought up in the ivory towers of football's elite, Sarri operated outside the hothouse, an amateur player at Figline, and worked as a banker.

He managed mainly in Tuscany for 22 years, working his way from semi-pro teams before reaching Serie A in 2014 with Empoli.

His tactics are a twist on conventional thinking. Essentially he asks players to take up defensive positions in relation to where the ball is, not where their opponents are standing. It means taking some brave, apparently crazy, positions at times.

Azpilicueta came through the youth ranks at Osasuna, the home-town team of Pamplona

'It is different,' says Azpilicueta. 'But it helps that he (Sarri) tells you very clearly what he wants and we analyse every game to see where we can improve. Defensively he says we want to be looking at the ball the whole time, high pressing. We're all working in training to get it as good as possible.

'Even though we had a good start, I think we can still improve. We're a very good team. We've been working very hard to get into that new idea of football. It is still September so hopefully there is some room for improvement.'

Azpilicueta absorbs lessons quickly. He is among the growing legion of highly-educated footballers. He came through the youth ranks at Osasuna, the home-town team of Pamplona in the Basque country in north-west Spain, but he stayed on at secondary school until the age of 18 to complete his high-school diploma.

'The club always checked we were doing well at school because we all know how hard it is to reach the top level. There are a lot who don't reach the highest level.'

Azpilicueta, it seems, was doing fine. 'I stayed at school until 18. When you're a kid, Osasuna is your club, from your home town. I was going to them every game. And then I was a 17-year-old making my debut when I was at school.

'Of course, all my friends were watching. I would go to the stadium with my school friends to watch the games and then a few days later, I was playing!'

Azpilicueta helped to oversee a PE lesson at Fulham Primary School near Stamford Bridge

The next Monday he was back at school, something of a sensation, but school allowed him to train as a professional in the morning and study in the afternoons: 'They had to help me and I made a big effort to finish high school and it was worth it.'

He passed exams to study at Pamplona University and even started his business studies course there before the demands of football became too much.

As such, he is both educational and sporting role model to the children at Fulham Primary School, a stone's throw from Stamford Bridge, where last week he was helping in a PE lesson as part of the Chelsea Foundation work.

From Osasuna he moved to Marseille, before making a largely unheralded switch to Chelsea in 2012, just after they had won the Champions League. He arrived with Eden Hazard, which explains why he was the less newsworthy of that summer's business. Arguably he has contributed as much as his friend.

Azpilicueta believes we are seeing the best of Hazard, now that the Belgian is developing a colder heart, on the pitch at least. He agrees, as Sarri said last week, that Hazard can be the best in Europe.

The Spaniard is determined for Chelsea to go all the way and reclaim the Premier League title

'I know Eden, we came here together and I played against him in France so I have seen him for a long time but, yes, I'm sure he can be the best. He has that quality of eliminating defenders. It's amazing. But this season he is adding goals and assists. Sometimes he was playing very good but maybe not selfish; he always gives passes to team-mates.

'Messi, Cristiano, they score 50 goals a year and that is very difficult in England. But from his point of view, if he's more aggressive in the box by scoring goals and making assists, he will be the top of his game. In normal play he can create chances. It looks very easy. He goes quick, he scores with both feet.

'Eden has all the qualities to be the best. And his personality as well, the way he behaves. He's the best player in the team but the way he respects everyone, he's a normal person. That's amazing to have the best player and his behaviour and everyone loves him in the club. That's as important as his work on the pitch.'

Azpilicueta believes his Chelsea team-mate Eden Hazard can be the best player in the world

Azpilicueta was part of the Europa League-winning team of 2013 but the Champions League remains the missing trophy on his Chelsea CV.

'Hopefully we can go to that level — first by qualifying! Now it's time to go step by step. Our target is to be near the top clubs in Europe.'

Azpilicueta won the Premier League in 2015 and 2017 but last season they were 30 points behind Manchester City. 'The gap was very big and obviously it was a disappointing season in the Premier League because we missed out on the Champions League.

'It's up to us to close that gap. We have to work hard and if we keep working the way we are doing, we can be close to City.

'We have to show it on the pitch. Off the pitch it's silly to talk about. Two years ago, when we won the title, it was opposite. We were top of the table and they couldn't get us.

'Mentality is key in winning the league. It's a very tough league and you have to fight against very good teams. No team give you any gifts. The moment to tell about this is on the pitch — and in May.'

Cesar Azpilicueta attended a Chelsea Foundation education and coaching session at Fulham Primary School as part of this season's Premier League Primary Stars Kit and Equipment Scheme. Primary school teachers can apply now for free Nike kit or free equipment via plprimarystars.com