Gareth Southgate admits the Premier League's shrinking pool of homegrown talent could force him to look outside the top-flight to fill his England squad in the future.
Southgate has named his first squad since England's run to the World Cup semi-finals as he prepares for the start of their Euro 2020 qualifying campaign.
After speaking to England boss Southgate, senior stars Gary Cahill and Jamie Vardy have stepped aside from international football to allow younger players the chance to come in, while Manchester United veteran Ashley Young was also left out.
But, in picking his group to face Spain and Switzerland next month, Southgate resisted the temptation to call up a number of promising youngsters.
Instead, he bemoaned the fact the number of eligible England players in the Premier League has dropped and pointed to the second tier as a way of potentially addressing the issue.
Stoke goalkeeper Jack Butland has retained his place despite the Potters' relegation last season and Southgate said: "I can't rule out players in the Championship now as our pool is getting smaller and smaller.
"There are so many positive things that have contributed to where we are now. But there is still this link between 17 to 21 where the bridge into first-team football and the financial power of the Premier League has a big impact, as does the precarious nature of managers in the top-flight in particular.
"I think it's worth us having that debate and getting people around the table to discuss that missing piece. If players are as good as any young players around the world then that opportunity needs to be there.
"If we are encouraging young players about entering academies, we are selling them the dream and there's an ethical element there too."