Borussia Dortmund and Benfica are two of the world's best run clubs. They've managed to stay afloat and competitive year after year despite not being the richest around by buying and developing young players, selling them on, and replacing them with brand new prospects.
They're set to play the second leg of their Champions League tie, with the winner going to the quarterfinals, and ahead of it we've put together the best combined XI of players sold by both clubs in the last 10 years.
Goalkeeper - Jan Oblak
There's no competition here. Oblak only played 10 games for Benfica, being loaned out a number of times while on their books.
In 2014, he took on the unenviable task of replacing Thibault Courtois at Atletico Madrid, and has developed into one of the world's best. No other goalkeeper Dortmund or Atleti have sold really even comes close.
Getty ImagesMaurizio Lagana
Defender: Mats Hummels
Mats Hummels was a Bayern Munich youth product, but he left for Dortmund in search of first team opportunities. He stayed at the club for seven years, becoming one of Germany's best defenders and playing in a Champions League final, before making the (almost inevitable) swap back from Dortmund to Bayern at the beginning of this season.
Defender: David Luiz
David Luiz started his European career at Benfica, staying in Portugal for four years before signing for Chelsea. Now, in his second stint at Chelsea, under the management of Antonio Conte, he's become one of the best defenders in the Premier League. Luiz has thrived under Conte's instruction, and he's grown perfectly into his role in the center of Chelsea's nearly impenetrable back three.
Luiz's passing range, astute reading of the game and natural aggression all lend themselves to the Blues' new system, and he's no longer the liability he was often known as in his first stint in London.
Defender: Ezequiel Garay
One of the Argentina national team's best defenders, Ezequiel Garay started his career in Spain, moving from Racing Santander to Real Madrid before eventually landing at Benfica. He stayed for three years, winning three trophies with the Portuguese side, before leaving for Zenit St. Petersburg in Russia. He then played two seasons there before finally landing back in Spain with Valencia in 2016.
Right midfielder: Henrik Mkhitaryan
Henrikh Mikhitaryan made a name for himself at Shakhtar Donetsk before joining up with Jurgen Klopp at Borussia Dortmund. He hit the ground running at the club, scoring nine goals and adding 10 assists in his first season, and he was one of Dortmund's very best players during his three-year tenure with Die Scharzgelben. Manchester United came calling in the summer of of 2016, and they shelled out £27 million plus bonuses to see him join the ever-growing ranks of Dortmund departures.
Center midfielder: Nemanja Matic
Another one of the youth treasures Chelsea compiled, let go, then re-acquired, Nemanja Matic joined Benfica from the Blues in 2011 as part of the David Luiz transfer. He left the the Blues after making just two appearances in the first team and landed at Benfica.
In Portugal is where Matic really found his feet, and he became a fixture in Benfica's midfield before Chelsea realized their mistake and brought him back for £21 million. He's been one of their most important players since then.
Center midfielder: Ilkay Gundogan
When healthy, Ilkay Gundogan was one of Dortmund's most important players. Gundogan cut his teeth in the Dortmund system, playing for five years, racking up over 100 appearances, and becoming a Germany international during his time with the club. A tempo-setting midfielder directly out of the Pep Guardiola mould, Gundogan finally decided to leave Dortmund in the summer of 2016, signing for a fee of around £20 million.
Left midfielder: Angel Di Maria
Benfica were Angel Di Maria's very first club in Europe, as the gangly winger joined from Rosario Central in 2007. He stayed in Portugal for three seasons and starred, earning a move to Real Madrid where he won himself a Champions League trophy.
Attacking midfielder: Bernardo Silva
One of Europe's brightest prospects right now, Bernardo Silva came through Benfica's youth system, but only ever made one appearance for the first team. He went out on loan to Monaco, then joined permanently, where he's currently lighting Ligue 1 and Champions League up. He probably won't be there much longer because every big club wants him.
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Attacking midfielder: Nicolas Gaitan
Argentine international Nico Gaitan joined Benfica from Boca Juniors in 2010. He became one of the club's best ever players, dazzling in a Benfica shirt for six years before leaving to join up with Atletico Madrid in the summer.
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Striker: Robert Lewandowski
One of the biggest coups Bayern Munich have pulled off in recent memory is signing Robert Lewandowski from Borussia Dortmund ... for free. Arguably the world's best striker (Luis Suarez may want a word), Lewandowski's scored a truckload of goals since signing for Bayern, won himself a couple league titles, and his Munich side are amongst the favorites to win Champions League this year.
Not bad for a free transfer.
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