“I just think it’s crazy,” says Eric Dier, who pauses for thought before confronting the hot topic of the summer at Tottenham Hotspur. “I always see now, when the big teams are doing badly, people say they need to spend another £200 million or £300 million. People are looking at the wrong things if they think they need to spend money to change things.

“It is so much more down to working with the players you have got, getting the best out of the players you have got, building something as a team. The culture you create at the training ground, the work you put in. The atmosphere, the relationship between the players.”

Given the total absence of new arrivals at Hotspur Way this summer, when Spurs were the only side in Europe’s top five leagues who did not make a single signing, it is tempting to assume that Dier is toeing the party line. He would say that, wouldn’t he? Yet the England midfielder speaks with such clarity, and such deep-voiced authority, that there can be no doubting the strength or authenticity of his beliefs.

He also speaks from experience. Dier has been an obvious beneficiary of this “culture” at Spurs, and he has seen his team-mates grow alongside him over the past four years. He knows what can happen when players are afforded the trust and the time they need to develop, because it has happened to him at the same time it has happened to Harry Kane, Dele Alli and so many of his Spurs team-mates.

“For me, people use it as an excuse,” Dier says of the modern urge to invest, to have what will be deemed as a successful transfer window.

Dier has developed alongside Harry Kane and Dele Alli credit: Reuters

“It’s the easy option to say ‘oh yeah, we’ll just spend £100 million on a player and everything will be OK’. It’s not the case.

“If you look to the past, and clubs that have been relegated recently, lots of them have spent a lot of money. They think that is what is going to make them better, but it is so far from reality. It’s all about the manager and the players who are at the club, creating that right environment and demanding everything from everyone every day.

“Improving every day, improving the players you have at your disposal and not looking elsewhere constantly. For me, you don’t understand if you think just spending money is going to resolve things. It’s so far from it.”

Dier’s views on the transfer market have naturally been shaped by Spurs’ achievements under Mauricio Pochettino, but they are also the product of an analytical mind. Fluent in Portuguese and with a passion for art, the 24-year-old has a reputation for being one of English football’s more thoughtful figures. He speaks lucidly on issues ranging from the dangers of social media to the financial health of the game and, unlike many of his contemporaries, appears more comfortable discussing these wider themes than he is talking about himself.

Spurs have started the season well despite not making a single summer signing credit: PA

“We have had to find different ways to achieve the same results as other teams,” Dier says. “People love to talk about the fact that we have not signed anyone, but we have got a fantastic squad. Why sign someone if they are not going to improve that? And secondly, we have got a fantastic atmosphere. We work extremely hard and the manager has installed that culture in the club. Every player has it. If they don’t, they won’t be welcome here. That’s more important than any amount of money you can spend.”

That said, it helps if you can spend wisely when you do pull out the chequebook. Spurs have not always done so under Pochettino, but there are signs this campaign that previous investments are starting to come good. The most obvious example is Lucas Moura, last season’s £25 million recruit from Paris St-Germain, who scored a brace in Monday’s 3-0 victory over Manchester United at Old Trafford.

That win, on that stage and against that opponent, felt like a potentially seismic moment for Spurs, who have won three games out of three despite nine of their players going without a pre-season after being involved in the last weekend of the World Cup.

“We have been together now for four years and everything is ingrained in us,” Dier says. “It’s really down to winning and that’s the mentality within the whole squad. I feel like it’s showed in all the games we have played so far. We have gone into them fully prepared to suffer if we have to, and to win. The Manchester United game, in the past that was the kind of game where maybe we wouldn’t have seen it out. But we went there and we got the job done.”

Dier scored the winning penalty as England banished their shootout woes at the World Cup this summer credit: Getty images

Getting the job done was what Dier managed to do, in dramatic circumstances, when he scored the winning penalty in England’s World Cup shoot-out against Colombia. He admits that moment has since been the “only thing that people talk about” when he is approached in public, but he also appreciates the magnitude of country’s first World Cup shoot-out victory. “The psychology changed when the player before me [Carlos Bacca] missed,” he says. “So I knew I was taking it to win, not to stay in it. That made a massive difference. When I was taking it to win it, I was just excited.”

He is also excited about the domestic campaign, which continues with Sunday’s trip to Watford. Javi Gracia’s side have also won all three of their league games, and should provide another early test before the international break.

“I think in order to succeed, you have to suffer,” Dier says.

“Suffering is good. We have suffered at times in the past three seasons. We have been through difficult periods, and this season we are going to go through difficult periods too. It’s down to us, what we do and the way we approach every game, every day at the training ground. If we do all those things right and we’re in the right mental space, then I think anything is possible.”