Image copyright Getty Images Image caption Jadon Sancho, Pierre-Emerick Aubameyang, Erling Braut Haaland and Christian Pulisic have all played for Dortmund

It is a little over two years since Jadon Sancho made his first league start for Borussia Dortmund but such is the club's commitment to youth, they are already talking about two even younger players to highlight their approach.

In December, Sancho became the youngest player to reach 22 Bundesliga goals, having already become the youngest Dortmund player to score 10 league goals in a single campaign in 2018-19.

His arrival from Manchester City for £10m in 2017 without playing a first-team game for the Blues is in line with Dortmund's recruitment policy.

"The way we do things didn't happen by accident, or by coincidence," said legendary Borussia Dortmund midfielder Lars Ricken, who is now the club's head of youth.

"It is a clear and obvious strategy not to buy superstars but to create them."

The German club stand to make a massive profit if, as expected, 19-year-old Sancho leaves in the summer for a fee likely to be in excess of £100m.

In January 2019, Dortmund sold another youth player, USA forward Christian Pulisic, then aged 20, to Chelsea for £58m , and immediately took him on loan for the remainder of the campaign.

Over the past seven months, Dortmund have done two more eye-catching deals. In January, they beat Manchester United to the signing of talented 19-year-old Norwegian forward Erling Braut Haaland , who has already scored eight goals in five first-team appearances.

And in July they brought Giovanni Reyna, son of former Manchester City and USA midfielder Claudio, over from the United States. He made his senior debut in January despite only celebrating his 17th birthday in November.

'We developed them to become superstars'

Dortmund's philosophy emerged from the financial crisis that brought the club to its knees in 2004, seven years after Ricken scored on the greatest night in the club's history, as they won the European Cup for the first - and so far, only - time.

Dortmund's last Bundesliga-winning team under Jurgen Klopp in 2012 included homegrown Mario Gotze and Mats Hummels, who joined them as an untested 19-year-old. Both were subsequently sold to Bayern Munich for a combined £60m.

"Ousmane Dembele and Pierre-Emerick Aubameyang weren't superstars when they came to Dortmund," said Ricken, who watched his under-19s side lose to Derby in a Uefa Youth League play-off at Pride Park on Tuesday.

"We developed them to become superstars. It is very important for the club.

"The reason the atmosphere in our stadium is so good is because there is a great identification between the players and the fans. The supporters see it is a gift for them to play in our stadium.

"We have signed some really good players but we also have young ones - Haaland is 19, Gio is 17. They are very light on their feet. It is great to see."

Speed is key

There is no great secret to Dortmund's recruitment policy.

Ask Ricken what features the club's scouts and coaches are looking for as they try to develop young players and the answer is universal.

"Technical skills are very important. And the quickness and speed of action," he said. "Players in our first team are all so fast. It is unbelievable.

"A few months ago, we had a player from a foreign country who was playing for our under-17s and he wasn't fast enough, so we decided not to make the transfer. It made no sense.

"The other thing is the mentality. The loads we put on the players are very high. School, football, national teams. This can all take 70 or 80 hours a week. These boys have to be grown-up, focused and disciplined at a very young age.

"Our aim is to educate players from Dortmund and the surrounding area. But if we find players from abroad with potential, we will take the risk to try and sign them. But we won't take them from the USA or England or Spain just to make our under-17 or under-19 team a little better.

"We want to find the special one. We were quite successful with Pulisic, Gio Reyna and Jacob Bruun Larsen."

Larsen is a Dane, who arrived at Dortmund as a 16-year-old in 2015 and was sold to Hoffenheim in January for £7m. Of their current crop of youngsters, Switzerland forward Bradley Fink - who is English qualified and attracting the attention of the FA - plus Dutch midfielder Immanuel Pherai and Cameroon forward Youssoufa Moukoko, who both played against Derby, are the current youth team stars.

Not like Reyna though, who has virtually bypassed the junior ranks.

"When Gio came to Dortmund, we knew he would become a professional player," said Ricken. "That was not the question.

"The question was when does he play for the first team? Summer? Winter? Three months? Six? Everybody was sure he would do it."

How to manage young players

While Dortmund view themselves as a successful football club and apply the same high standards in their junior ranks as they do at senior level, they also acknowledge a wider responsibility to the young players who come through their system with dreams of emulating Gotze, who scored Germany's winner in the 2014 World Cup final against Argentina.

"If they have problems in school or in other parts of their lives, we want to solve them. We have social workers here. We don't just choose our coaches because of their training skills but because they have wider abilities," said Ricken.

As Borussia Dortmund have the highest average attendance in Europe - almost 80,000 - and were ranked 12th in the latest Deloitte Money League released in January, a single trophy - the German Cup - since Klopp won the double in 2012 seems a poor return.

Manager Lucien Favre is the fourth man in five seasons to try to emulate Klopp's achievements, so while demands are high, Ricken believes fans provide an environment that allows youngsters to continue to progress.

"Halfway through the last season under Jurgen Klopp in 2014-15, we were 17th in the table," he said.

"But the supporters were so thankful for the times they had before, that when we lost another match they still gave the players a big hand to give them courage for the next matches.

"Trophies are very important but, especially in Dortmund, the attitude you are playing with, the passion, emotion and never giving up is as important."