Players' union chief Ko Andriessen is calling on the KNVB to intervene.
"We cannot bet on youth training if at the same time the first teams are increasingly filling up places with youth from foreign clubs. We are threatening to become a satellite competition and a few strategic choices have to be made very quickly.
"It's about balance. I understand that top talents such as Mason Mount and Angeliño have really added something. Only it should not be the case that whole armies are randomly dropped here."