In recent years, the Football Association, which governs the game in England, has made an “enormous investment” in youth development, according to Gareth Southgate, the manager of the England senior team, as part of a program to identify and develop the best young talent. That is in addition to spending hundreds of millions of pounds on facilities at the national teams’ base at St. George’s Park.

There has been no small emphasis on outreach, too, building better relationships with clubs, encouraging them to release their young players for international duty. Premier League teams have done their part, too, focusing more and more time and resources on nurturing young players: not just building state-of-the-art academies to house them, but taking practical measures to help them grow.

Some, most notably Chelsea and Manchester City, have arranged strategic loan partnerships in order to expose young hopefuls to first-team soccer. All agreed to a revamp of what was once, variously, the reserve or the under-23 league, now rebranded as Premier League 2.

A mandated number of its games have to be played in a club’s home stadium; many are broadcast live, either on television or through teams’ websites. The aim is to turn what used to be an afterthought into a closer version of competitive soccer.

The summer of 2017 was taken, then, as the moment that all of the money and the manpower started to pay off, a reward for the time and effort expended to help England punch its weight at international level again.

And yet, for all the triumphalism, Klopp was not the only observer to strike a note of caution. Even after the world had been conquered — not once, but twice — there was still a sense that the greatest challenge for all of these players was still to come. “People in any industry need opportunity,” Southgate said. “You can have the best education system going, but if people do not have the opportunity to display what they can do, then it is difficult to develop.”