Jürgen Klopp is calm and serene. His face lights up, of course, at the prospect of “the mighty battle” which awaits Liverpool on Tuesday when Roma arrive at Anfield for the first leg of their Champions League semi-final. He also leans forward animatedly when assessing the intriguing challenge the Italians will pose. Yet, beyond the cliche of Klopp as a madly gurning cheerleader on the touchline, the 50-year-old German proved, again, his tactical nous and inspirational management while guiding Liverpool to three victories this season over the feted Premier League champions Manchester City. The 5-1 aggregate defeat of City in the quarter-finals was exhilarating and resilient.

It is striking how, at Liverpool’s training ground, Klopp is also stimulated when discussing real life and tangled politics, Brexit and Angela Merkel. There are moments in a free-wheeling conversation when the hilarity feels unstoppable as Klopp considers a claim that he would win an election to become German chancellor because of his attention to detail, communication skills and empathy. But there are many more thoughtful moments – particularly when Klopp addresses the vexed issue of Brexit and his belief that British people should have the chance to vote again on their future in or outside the EU.

Brexit makes no sense and Britain should vote again, says Jürgen Klopp Read more

We start, however, with Klopp reminiscing about his youthful desire to become a doctor. That teenage ambition chimes with his persistent interest in helping people “get better every day” and his work with players, from Mo Salah to Dejan Lovren, who improve in contrasting ways.

“I was young when I thought about becoming a doctor,” Klopp says with a smile as he remembers growing up in the Black Forest village of Glatten. “I had the idea three years before my A-level. But to study medicine your A-level results had to be fantastic. So it was good for all the people who would have been under my knife that I didn’t make it. But it was close to be honest.”

That wistful sentence is swamped by his laughter. But the idea of Dr Klopp is not outlandish. He exudes a warmth and intelligence we would all want to see in a doctor. “I have this helping syndrome,” Klopp says. “I really care about people and I feel responsible for pretty much everything.”

Klopp’s inclusive leadership, ensuring everyone feels nurtured and needed, is at the root of his success. Is he also becoming a scouser as his immersion in Liverpool runs so deep? Klopp grins, brandishing his cup: “There’s this tea, for example. When we come somewhere new my family like to adapt. We want to live like people here. I’m not a guy who says: ‘By the way, I want to tell you in Germany we do it like this or that.’ We look so similar but we are very different too. It’s really interesting. My boys both work in Germany but they are football maniacs so they’re very often here. They tell me about the nightlife and I experience the country in the daytime.”

Does life on this small island seem insular, particularly when the political landscape has shifted dramatically since he arrived? “I’ve heard it said that English people are not looking outwards but I don’t see it. I live in Formby and work in Liverpool. I drive from here to there and sometimes I’m in different cities for games. So I don’t know enough about the country but many people come to Britain because English is the language the world speaks.

“I can’t say Germany is more open. If you ask the wrong people in Germany they would say: ‘Yes, we want a fence to keep foreigners out and, by the way, could you make is as high as the [Berlin] Wall.’ Europe has been strange the last few years. I like to go to Austria for skiing but they only push [immigrants] through to Mrs Merkel. Being a leader in this situation is not a joy. There is no easy solution.”

Facebook Twitter Pinterest ‘It’s a difficult job to be Liverpool’s goalkeeper,’ Klopp says. ‘I’m not sure who was the last goalkeeper everybody was happy with here. And if you are not Sami Hyypia then your life as a defender is also difficult.’

Portraits: Christopher Thomond/Guardian

The option favoured by the Brexiteers, however, seems misguided and dispiriting. “I understand,” Klopp says. “I’m not the best-informed person but I’m very interested in it. When Mr Cameron had the idea [of a referendum] you thought: ‘This is not something people should decide in a moment.’ We are all influenced by the way only some of the argument is given, and once the decision is taken nobody gives you a real opportunity to change it again. The choice was either you stay in Europe, which is not perfect, or you go out into something nobody has any idea how it will work.

“So you give people the chance to make this big decision. And then it’s a 51-49 [51.9%-48.1%] vote and you’re thinking: ‘Wow, 49% are not happy with the decision that’s going to change the country.’ For the 51%, I’m sure they realised pretty early after the vote: ‘What have we done?’

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“The two leaders of the Leave campaign then stepped aside. It was a pure sign they were surprised themselves by the vote. OK, that can happen. But then, come on, let’s sit together again. Let’s think about it again and let’s vote again with the right information – not with the information you’ve got around the Brexit campaign. They were obviously not right, not all of them. It makes no sense at all.

“When I speak to people they say: ‘I wanted to stay [in Europe] but I don’t want to talk about it because I don’t feel it yet as a person.’ I feel it constantly because since I came here the pound dropped. People go on holiday and say: ‘Spain is very expensive!’ But it’s only because the pound is not that strong any more. The EU is not perfect but it was the best idea we had. History has always shown that when we stay together we can sort out problems. When we split then we start fighting. There was not one time in history where division creates success. So, for me, Brexit still makes no sense.”

Dejan Lovren is strong, quick, both feet, can head like crazy, jumps through the roof. He’s all you need.

This embrace of Europe does not mean Klopp is disparaging towards British footballers. More than most Premier League clubs he has an English core to his squad. Jordan Henderson, James Milner, Alex Oxlade-Chamberlain, Adam Lallana, Trent Alexander-Arnold, Joe Gomez, Nathaniel Clyne, Dominic Solanke and Danny Ings are joined by other bright young talents such as Scotland’s Andrew Robertson and Wales’ Ben Woodburn.

“They are here because they’re really good – not because they’re English or British. But if you have two players at the same level and one is English and the other is from somewhere else I always go for the English guy. They keep the mood good and for them it’s easy to feel the club’s history. But we have fantastic boys from all over the world and they love the club. Roberto Firmino has such a Liverpool heart. But the English guys lead the group. Tottenham and us we are pretty much the English national team and I like that.”

Liverpool’s, and the PFA’s, Player of the Season is Egyptian. Salah faces his former club on Tuesday. Klopp’s acumen in signing Salah from Roma has been underlined and a £35m transfer fee now smacks of a bargain. “Mo did very well at Roma but they have Edin Dzeko who is an outstanding striker. So it was their tactics to sometimes play him wide. Now, a year older, he came to us full of confidence. He scored in the first game but missed two big chances. So, unbelievably, he could have scored much more [than the 41 goals Salah has this season]. We have learned about him step by step because he plays constantly in the same position. This season is more about interpretation [of his goalscoring talent] and because Bobby Firmino is a workhorse he really gives Mo space. I’ve had many talks with Mo and he sees what the others do for him.”

Facebook Twitter Pinterest Mo Salah scores his 41st goal of the season, at West Brom on Saturday. ‘I’ve had many talks with Mo and he sees what the others do for him,’ Klopp says. Photograph: Andrew Yates/Reuters

Did he spend much time assessing Salah’s character before signing him? “I always meet the player before we sign. That’s when I decide because I have a good feeling for people. It was a fantastic talk. He’s open, smiling all the time. He has crazy curls but he’s a really nice boy. He also looked much more mature than it says on his passport. Twenty-four? I was: ‘Wow, really?’ We talked for three hours about everything from his family to my family and at the end we had a deal to work together. I like to remind players from time to time of that agreement. It’s working really well with Mo.”

Lovren has had a more testing season and mistakes against Spurs and Manchester United meant that many Liverpool fans denounced him. But his resurgence has been marked and, against City, he was a clear leader. “There are some really difficult things in Liverpool,” Klopp says. “The whole Liverpool family is not happy with not winning big trophies since whenever – so you always find a reason. ‘The problem is we don’t spend enough.’ Or, ‘The players make mistakes’. So, really, it’s a difficult job to be Liverpool’s goalkeeper. I’m not sure who was the last goalkeeper everybody was happy with here. It would be a while ago. And if you are not Sami Hyypia then your life as a defender is also difficult.

“I don’t exactly know about Dejan’s start at Liverpool but he made a few mistakes. People always have that in mind: ‘Oh, Lovren again!’ But I’m long in the business. I said to Dejan: ‘If somebody told me, come on, you have the chance, create a centre-half. We found a way to do it, genetically, bam, bam, bam.’ That’s him, strong, quick, both feet, can head like crazy, jumps through the roof. He’s all you need. Yes, a few things you can improve – his concentration. But these are human beings.

I love the job but if somebody told me: ‘If you carry on you will die much earlier’ then I’d say: ‘I’m on the road home’

“Other centre-halves make mistakes. Against City, Virgil van Dijk, an outstanding person and fantastic player, should have cleared the ball before they scored. Virgil knows that. But nobody spoke about it because we won. It doesn’t look like it but I’m really relaxed in judging these things. When I see talent, and I’m convinced, I am calm.”

Liverpool now face a formidable test – despite a widely held belief that Roma are the weakest club in the semi-finals. “Roma are interesting,” Klopp says. “We’re expecting a mighty battle. They have Dzeko, they brought in the young Czech guy [Patrik] Schick and the young Turk [Cengiz Ünder]. Fantastic. [Daniele] De Rossi controls the midfield. Their defence is really experienced. Alisson is a fantastic goalkeeper. They beat Barcelona. They were first in their group, they didn’t concede a goal at home so far in the Champions League. There are many impressive things about them.”

It helps that Klopp has been here before although, when we remember our previous interview, before Dortmund lost to Bayern Munich in the 2013 Champions League final, he grimaces. “I’ve never watched it back. It’s too painful.”

Manchester City felt Champions League pain against Liverpool – but soothed themselves by winning the league with five games to spare. How close are Liverpool to a concerted tilt at City’s title next season? “It’s an interesting question because while we improved a lot they do the same. You can’t imagine that City, after a brilliant season, will say: ‘Oh, that’s so good we’ll keep the same squad.’ They will find new players. I also noticed an interesting thing. Their club has more money than every club in the world but I saw the City boys celebrating in a really nice way in the pub. It showed a real team.”

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It has been another draining season but Klopp looks fit and well. He was said to have suffered a minor health scare in November when he went to hospital. “We all go for a check now and then but nobody knows. It was actually a funny situation. They tried to bring me in through the back door but the security guy has a walkie-talkie and he says: ‘Klopp is in the house!’ But, really, I’m fine. I love the job but if somebody told me: ‘If you carry on you will die much earlier’ then I’d say immediately: ‘Thank you. I’m on the road home.’”

He looks intrigued when I point out that, after spending seven years each at Mainz and Dortmund as manager, his Liverpool contract runs until 2022. He will then have completed a third seven-year stint at a club with whom he has fallen in love. “The seven years is a coincidence. When you have a marriage and if you’re past your seventh year then you’re OK. But, actually, I don’t need this kind of settling. It’s not in my nature. But when I am in a club I am in it totally.”

Liverpool are lucky to have him but, thinking of that seven-year cycle, I joke with Klopp that some people have another job in mind for him. Martin Quast, a German sportswriter, said: “If Klopp wanted to run for German president, he would get elected. He would bring people together, lead the way, make people happy.”

Facebook Twitter Pinterest Borussia Dortmund fans showed their appreciation to Jürgen Klopp before he left in 2015 after seven years. If he sees out his Liverpool contract he will have spent seven years there too. Photograph: Ina Fassbender/Reuters

After Klopp has stopped laughing he explains that Quast is from Mainz. “Maybe in 2004 I could have been chancellor of Mainz. But I have absolutely no skills apart from being interested in politics. I would enjoy it if a politician spoke like a normal person but the job is complex. So we should care about our good people in politics because there’re not many of them. It’s like being a football manager. Many people are interested in football but only a few combine all the skills. Politics is even more difficult. I could never do it – or want to do it.”

Klopp as German chancellor would still be fun and maybe he could find a way to help Brexit Britain. “Hmmm,” Klopp says with mock seriousness. “Angela Merkel has two weeks off a year. That’s less holiday than I have which means that’s absolutely not my target. On holiday everybody is following her. She’s in the mountains having a nice hike and every year the same picture of Angela and her husband. I really like her and she’s doing an unbelievable job. But it’s a very difficult job – which is not as well paid as a football manager either. I will stick with Liverpool.”