When he was three years old Dejan Lovren’s family had to flee Yugoslavia or “somebody would have been killed”.

The central defender billed by Brendan Rodgers as Liverpool’s new Jamie Carragher endured a childhood that can hardly be imagined. Yet Lovren maintains this was crucial in forming an inner strength that has helped his rise to be the marquee summer signing for the five-times European champions. No wonder Rodgers views Lovren, who cost £20m from Southampton, as a natural leader despite being only 25. The man whose goal secured Southampton a fine win at Anfield last season is intelligent and open, willing to engage in debate and offer a range of opinions formed by his own experiences that include a challenge to those on these shores who believe immigrants can never be a force for good.

Born in Zenica in what is now Bosnia-Herzegovina, Lovren and his family fled to Germany from his home town in 1992, 12 months before 15 people were massacred when its market was bombed. Eight years of agonising uncertainty in Munich ensued as Lovren lived under the threat of being deported with his parents. After finally being ordered to leave, Lovren arrived as a stranger in Croatia and could hardly speak the language of the country he went on to represent in the World Cup this summer.

Lovren, who will make his senior debut against his old club at Anfield on Sunday, says: “The family left because of the war. If we stayed, somebody would be killed. It was horrible in this time – we were prepared to go to Germany, my parents took the decision and said: ‘We don’t have a choice any more.’ My father and mother’s parents were already there so we were the last. We took the bags, one little car, and we were in Germany.

“There was an attack on the market a year after we left. A lot of people were killed. It showed to me it is a difficult life. It was really difficult for my parents to leave the country at 27, 28 years old, and say: ‘Come on, we need to go to Germany.’

“You don’t speak German, you don’t know anything about this, you are going like a blind man and, with a child like me at three years old, this was really difficult for the family. But this is what gave something to me, it made me stronger inside. It showed me life is never easy, you will earn everything with work. I saw everything on my parents, and I said to myself: ‘I don’t want to live my life like this.’ They gave me everything they could but it was not amazing.”

Of his family’s deportation for effectively being illegal immigrants, Lovren says: “We didn’t have the right papers. My grandfather yes, because he left Bosnia two years before the war, so he had the papers for my grandmother, but not for my father and mother.

“It was difficult. A lot of people were trying to go to Germany because of the war and they couldn’t give [permission] to everyone. I think after seven years in Germany the situation calmed down and we went back in 1999.”

Lovren’s family settled in Karlovic, a town south-west of Zagreb, Croatia’s capital but new problems emerged. “It was really difficult for me because I had many friends [in Munich]. I had three years in the nursery and four years in the school. I was German-speaking, and I arrived 10 years old to Croatia, and really wasn’t speaking a lot at home with my parents in Croatian, so it was really difficult to write in Croatian,” he says. “It took me two years after I went back to learn everything again in Croatian. It was difficult because you know, when you’re a kid, the others kids are laughing at you over things like that.”

Although Lovren had played for a small club in Munich there were no dreams of life as a footballer. “I never expected that I would be somebody. I just started playing and when I was 12, 13, thought: ‘Wow, I’m playing good.’ Then Dinamo Zagreb were speaking about signing me, I thought: ‘Hmm, maybe I can achieve something.’

“But I was just a normal child. I had a dream about Bayern Munich, they were my team. I had my photos taken with Giovane Élber, [Mario] Basler, [Bixente] Lizarazu. I have all these pictures in my room. I would go to the training ground to see them. The guys here [outside Melwood, Liverpool’s training ground] waiting? That was me.”

He will not say his upbringing made him more determined but adds: “I would say I’m proud about this. I know where I came from, it will always be in me. Maybe it was better to happen like this, than maybe to have a good childhood when you don’t know the real life.”

While some hold that immigrants can never be a positive addition to society, Lovren reflects on how the chance of a fresh life in Germany was the catalyst for his career. “Yeah, of course, but it was normal in Germany at that time to accept immigrants after the war. What can you say to them? Say ‘No’ and send them back and they will be killed? I understand the situation and still I’m here as a stranger but everyone needs to accept [those] who will work for this country and who will make money for this country. These people deserve to be here.”

After joining Dinamo in 2006, Lovren won two championships in four years before moving to Lyon for £8m. He helped win the French Cup and took part in two Champions League campaigns during his three and a half seasons there, before last summer’s £8.5m move to Southampton.

Lovren came close to joining Liverpool while at Lyon, where he endured a hostile time. “They criticised me in many ways,” he says. “Even from the beginning when I arrived. They were asking: ‘Why is this guy €10m?’ It was always: ‘Why this? Why this? Why this?’ Always something. When I was playing good, nobody was saying I was playing good. When I was playing bad, I would be the first one on the front of the journal. It wasn’t easy for me. They didn’t respect me as a player.”

Lovren, who has 28 Croatia caps and scored on his Liverpool bow – Sunday’s 4-0 hammering of Borussia Dortmund – shrugs when asked about the Carragher comparison. “The manager said he sees me like a leader. I said to him: ‘I’m still young. I’m 25, but I will try my best. I will lead the team.’ I don’t have so much experience like Jamie Carragher but it will come and it is a great honour to be compared by the manager with a player like that.

“I like to talk during the game, I like communication with the lads – to keep me awake apart from anything else. But it’s the beginning.”

Liverpool finished an impressive second last season. Of the club’s title hopes, Lovren says: “I can’t say that we can win it but we have a really good chance. Chelsea, Arsenal, Manchester United, also Manchester City. They are the ones. It will be tight, like last season, but we will be here fighting. I think it will be even better than the last year.”