United States coach Jurgen Klinsmann used the example of Borussia Dortmund forward Christian Pulisic to highlight his concerns about youth development in the national game.
Pulisic, born in Pennsylvania, made nine Bundesliga appearances for Dortmund in his breakout campaign, scoring twice.
Klinsmann doubts whether a 17-year-old would get the same chance to shine in MLS, and called for greater opportunities to be given to young players in the USA.
"We struggle traditionally with our 18 to 23-year-old generation," said Klinsmann.
"Who would have given Christian Pulisic a chance here [in MLS] as a 17-year-old to play?
"Here, in the US you call a younger player a rookie at the age of 22. At 22 in Europe, if you're not broken through yet, you're done. They move you down to third or fourth level.
"A lot of pieces fit into that question, but in general you have to give them more belief, you've got to give them more opportunities, you've got to let them make mistakes."
Klinsmann highlighted the progression of DeAndre Yedlin, who was promoted from the youth team at Seattle Sounders, and Hertha Berlin defender John Brooks as examples to follow.
"I think DeAndre is an exception. John Brooks fought his way through now, but we need more," continued the German.
"We need to give them more support. They also have to help themselves more. But if you don't give younger players a chance, how do you want them to break through?"