England's Under-20 World Cup success would not have been possible without the co-operation of Premier League and EFL clubs, says Football Association technical director Dan Ashworth.
A 1-0 win over Venezuela in Sunday's final in South Korea gave England their biggest international title since 1966.
Ashworth has written to the clubs to thank them for releasing players before the end of the season.
"Without the relationships with the clubs you can't compete," he said.
Everton manager Ronald Koeman allowed five youngsters to miss the final fortnight of the Premier League season to prepare for the tournament, including Dominic Calvert-Lewin, who scored the only goal in the final.
Of the 21-man squad, 16 played senior league football this season, while seven of these played for a Premier League team.
"I have sent a note to thank all the clubs, we are eternally grateful", Ashworth told Eyes On Events Sport. "Without players being released we would not have been able to compete in the World Cup.
"It's not just the World Cup, it's every international event when we need the help of clubs in order to release players to play international football at development team age. We have a good relationship with the clubs and we are really grateful for that."
Ashworth said Paul Simpson's side's success is a "sign of things working well in youth development in this country".
Ashworth lists three factors in their success:
- The FA's National Football Centre at St George's Park, which opened in 2012 and the coach education offered there;
- "Excellent" work by coaches and clubs at academies that have "pushed on" with youth development;
- "Revolutionary" new coaching qualifications.
He added: "A lot of work has gone into this World Cup triumph. England do get stick and unfair criticism, but Sunday was for everyone involved in youth development in England."
'Our players are as good as any in the world'
England forward Dominic Solanke, due to join Liverpool from Chelsea on 1 July, was awarded the Golden Ball, given to the player of the tournament. Previous winners including Diego Maradona, Lionel Messi, Luis Figo, Paul Pogba and Sergio Aguero.
Newcastle goalkeeper Freddie Woodman, who saved a second-half penalty in the final, was awarded the Golden Glove, given to the best goalkeeper of the tournament.
"I believe things like winning the World Cup will firmly help players prove that our 19 and 20-year-olds are as good as anyone else in the world, they proved that with Sunday's success," added Ashworth.
"Premier League managers are not silly people, if they see players that can help them keep jobs and win games and make the academies work then they will certainly play those players. Let's hope England's success has helped a few of those players establish themselves in their first teams."
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Ashworth praised the Checkatrade Trophy for giving opportunities to young players.
The EFL was criticised heavily after teams from the Premier League and Championship with Category One academies were invited to compete against lower-division sides.
"I am a fan of the trophy, " he said. "It is a good concept to give players the opportunity of playing against senior players in a results driven and meaningful competition. It will help them establish themselves and learn tricks of the trade in becoming established senior professionals themselves."
He added: "There is no right set pathway to follow for youth development to the Premier League, to becoming a senior England international. Twenty one players came to the World Cup, there are probably 21 different solutions. It depends on each player, what do they need?
"I recognise the gap between an 18 and a 23-year-old - the challenge for all of us, is to get players some meaningful game time to stretch and push them.
"Some of that will be an under-23s training programme, some of that will be a loan period, some of that will be international exposure - for most of them it will be all three of those."
Despite the criticism it received, a revamped Checkatrade Trophy will continue next season.
'The culture has to be right to keep players'
Ashworth also addressed concerns about players switching allegiances to another country after representing England at youth level.
There have been high-profile moves - Crystal Palace winger Wilfried Zaha opted to play for Ivory Coast, while Chelsea's Victor Moses and Arsenal's Alex Iwobi switched to Nigeria.
"It is up to us to make sure we set the environment and culture that the players want to continue to play for England," he added. "If we do not select them for a couple of years, then I understand them wanting to play for another country.
"But we can't have everyone available. Gareth Southgate can only pick 23 players each time he calls up a squad.
"It is unlikely people will play for the England senior team without being a Premier League regular, but it's not right to point the finger, saying if you're not playing in Premier League then join another country, we have to make sure they are desperate to play for England."
Dan Ashworth was speaking to Eyes On Events Sport's Simon Stone.