Europa League finalists Ajax and Manchester United both have a rich history of producing their own players.
Here, we pick their all-time homegrown XI.
Goalkeeper: Maarten Stekelenburg
Edwin van der Sar joined Ajax at the age of 19, so current Everton number one Stekelenburg gets the nod with nearly 60 Holland caps and two Eredivisie titles.
Right-back: Wim Suurbier
Made his senior debut at the age of 19 and played nearly 400 games, his attacking adventure played a key role in Ajax's 'Total Football' philosophy of the 1970s.
Centre-back: Toby Alderweireld
The Belgian defender joined Ajax's academy at the age of 15 from Germinal Beerschot. Established himself as one of the world's best centre-backs in two seasons at Tottenham.
Centre-back: Frank de Boer
A stylish defender who captained Holland at both the 1998 World Cup and Euro 2000, won domestic and European trophies at Ajax before joining Barcelona.
Left-back: Ruud Krol
Versatile operator who could play anywhere across the back line, tough-tackling mainstay of the great Ajax side which won three consecutive European Cups in the 1970s.
Midfield: Frank Rijkaard
Brilliant defensive midfielder who progressed from the academy into the first team at just 17 years of age, and won two European Cups at AC Milan before returning to Ajax and winning a third in 1995.
Midfield: Edgar Davids
Ferocious competitor nicknamed "The Pitbull" by Louis van Gaal for his aggression and hard-tackling style of play. Helped Ajax to Champions League glory in 1995 before moving on to Juventus.
Midfield: Clarence Seedorf
Became club's youngest-ever debutant aged 16 in 1992, and won the Champions League with Real Madrid and Milan as well as Ajax - the first player to do so with three different clubs.
Striker: Sjaak Swart
The man they called "Mr Ajax" made the most appearances for the club (596) and scored an incredible 217 goals from his right-wing berth in helping them to three European Cups and eight Dutch titles.
Striker: Johnny Rep
Fine finisher and scored winner in 1973 European Cup final against Juventus, edges out Patrick Kluivert who repeated the feat versus Milan in 1995 at the age of 18.
Striker: Johan Cruyff
One of the greatest players to ever grace the game. Playmaker, provider and finisher rolled into one and won three European Cups before becoming a hero all over again in Barcelona.
MAN UNITED XI (4-4-2)
Goalkeeper: Jack Crompton
Began his youth career at Oldham and Manchester City before moving to Old Trafford in 1944 where he spent 12 years, winning the FA Cup and the league title.
Right-back: Gary Neville
Dependable full-back made over 600 appearances in 20 years and won just about every honour in the game. Also won 85 England caps and went on to become club captain.
Centre-back: Bill Foulkes
A no-nonsense defender who survived the 1958 Munich air disaster to become enshrined in United folklore, racking up 688 first-team games and part of the team which won the European Cup in 1968.
Centre-back: Duncan Edwards
The powerful wing-half could play anywhere and gets in this team in central defence. Played over 150 times for United and won 18 England caps before perishing in Munich at the age of 21.
Left-back: Roger Byrne
The United captain was another to lose his life at Munich. Loved to power forward and join attacks and had won 33 England caps by the time of his death at the age of 28.
Midfield: David Beckham
Wonderful crosser and long-range shooting skills were responsible for many of his 86 United goals. Captained England for six years and won 115 caps in becoming a celebrated national figure.
Midfield: Bobby Charlton
Guided United to European Cup glory in 1968 after surviving Munich. Spent 17 years in first team and United's all-time leading goalscorer (249) before Wayne Rooney eclipsed his record in 2017.
Midfield: Paul Scholes
Started out just behind the main striker, but sublime passing ability saw him drop deeper to dominate games and become a feared free-scoring midfielder - his final return being 155 goals in 718 games.
Midfield: Ryan Giggs
Spent 23 years in the United first team as he morphed from the tricky left-winger of his youth to an intelligent central midfielder, making a record 963 appearances for the club in the process.
Striker: George Best
The complete forward whether operating down the wing or playing through the middle. One of the greatest dribblers of all time, scored 179 United goals and was a European Cup winner in 1968.
Striker: Dennis Viollet
Formed a terrific strike partnership with Tommy Taylor as the 'Busby Babes' dominated English football pre-Munich. Like Best, scored 179 United goals to be joint fifth on the club's all-time scoring list.