Gareth Southgate has warned that England's future stars are being pushed into the national team too quickly.
The new Under-21s manager believes the influx of players from all over the world has blocked the path for youngsters looking to break through the ranks at their respective clubs and as a result, the pool of talent from which senior boss Roy Hodgson has to pick has been reduced.
Southgate's comments came after Everton teenager Ross Barkley and Tottenham's Andros Townsend, 22, were included in Hodgson's squad for the forthcoming World Cup qualifiers against Moldova and Ukraine.
Southgate told talkSPORT: "The big problem historically for any young player getting into a first team is managers who are under pressure in their jobs deciding whether they take a chance on a young player or not.
"That was the same when I started at Crystal Palace and it's still the same now. The difference is the players blocking their path are now from all around the world. In the old days, all those players were English or British.
"The pool of players Roy Hodgson has to pick from is far smaller than before, but I think the pool of players I have to pick from at Under-21 level who are getting into first teams isn't a lot different.
"You won't get many kids of that age playing top-flight football week in, week out. It's just very unlikely.
"The issue I think we have is that, with the seniors, there is a smaller pool of players playing regularly and then we're having to push through younger players that are playing maybe earlier than we would ideally like to."
Meanwhile, the Football Association has confirmed that Chelsea coach Steve Holland will assist Southgate for qualifiers against Moldova and Finland as he prepares to take charge of his first matches over the next week or so.
Holland, assistant first-team coach at Stamford Bridge, began his coaching career under Dario Gradi at Crewe, where he spent 17 years, and joined Chelsea in 2009 after a spell at Stoke.