Borussia Dortmund are one of the most well-known teams in Europe.
Their incredible scouting network has captured the hearts and minds of football fans for over a decade, going on to enjoy incredible success under Jürgen Klopp, despite their limited resources compared to other teams on the continent.
But the Black and Yellows also boast one of the most impressive academy systems, notably producing players like Mario Götze, Michael Zorc and most recently Christian Pulisic.
Just like with any great academy system though, quite a few players have passed through Borussia Dortmund's door which aren't as well known for one reason or another.
Here's seven such players...
Borussia Dortmund career: 2008-11
Chelsea centre back Antonio Rüdiger is best known for impressing in Serie A before his move to west London, and even though his breakthrough in Germany actually came with Stuttgart, the 27-year-old spent three years in Borussia Dortmund's youth system.
Rüdiger was born in Berlin and before joining Dortmund in 2008, the Germany international had spent time with four different youth sides in the capital.
Less than one year after leaving Borussia Dortmund, Rüdiger made his senior debut in the Bundesliga and he's gone on to make 287 appearances throughout his career at club and international level.
Borussia Dortmund career: 2001-11 & 2014-18
Borussia Dortmund are certainly the first club many will think of when they see the name Nuri Şahin, but what many won't realise is how the Turkey international actually spent four years in the club's youth system before making his record-breaking debut.
Şahin became the youngest player to even feature in a Bundesliga match in 2005, starting alongside Tomáš Rosický and Florian Kringe in midfield during a 2-2 draw against VfL Wolfsburg.
Borussia Dortmund career: 2006-13
Daniel Ginczek might not be a name which rings too many bells for fans outside of Germany, but the 29-year-old has been one of the country's standout strikers in the Bundesliga in recent years - and could have had quite the career had it not been for injuries.
He was forced to drop down the footballing ladder and work his way back up after leaving Borussia Dortmund in 2013, but Ginczek's continued to struggle with his fitness and he's been forced to miss 116 games throughout his career due to injuries.
Ginczek never actually made an appearance for Borussia Dortmund's first team, although he was included in their matchday squad five times.
Borussia Dortmund career: 2003-09
Though he hasn't had the career that many expected, Tolgay Arslan has enjoyed somewhat of a revival since moving to Turkey.
The former Germany Under-21 international was never given a chance in Dortmund's first team, but it was at his next club Hamburg where Arslan really started to show signs of promise.
Arslan's career took an unexpected nosedive and he eventually left Germany in 2015 to join Beşiktaş, but since then a transfer window has rarely gone by without the midfielder being linked with a move back to the Bundesliga.
Borussia Dortmund career: 1998-2012
Chelsea have two well-known academy graduates from Borussia Dortmund, but Daniel Farke's Nowrich City have also dipped their toes into the Black and Yellow waters in recent seasons.
As well as Moritz Leitner, Marco Stiepermann was also on Borussia Dortmund's books before eventually moving on in 2012, where he was forced to work his way up Germany's football pyramid.
Stiepermann made seven appearances for Borussia Dortmund and even scored for his hometown club too, netting a late equaliser against Wolfsburg in 2010.
Borussia Dortmund career: 1995-2005 & 2012-present
Most of Marco Reus' senior career has been spent at Borussia Dortmund, but the 30-year-old was actually forced out of their academy system as a youth player.
Reus didn't make his first senior appearance until he joined Rot Weiss Ahlen, but the Germany international's most notable impact came working under Lucien Favre at Borussia Mönchengladbach.
Since returning to Borussia Dortmund, Reus has made 266 appearances for the club and he's even picked up the captain's armband.
Borussia Dortmund career: 2007-08 & 2011-13
Kerem Demirbay has emerged as one of the most talented midfielders in the Bundesliga in recent years, but the German was deemed to be not good enough for Borussia Dortmund on two different occasions.
He initially joined the club from bitter rivals Schalke in 2007, but Demirbay's first spell at Borussia Dortmund only lasted for one season. He spent the next three years on the outskirts of Bochum with SG Wattenscheid 09, but he was eventually invited back to the Westfalenstadion in 2011.
Demirbay left for good in 2013 and joined Hamburg, going on to have his breakout spell at Hoffenheim before earning a £28m move Bayer Leverkusen at the start of the 2019/20 season.