England U21 coach Aidy Boothroyd says they must be careful with the development of Fulham superkid Ryan Sessegnon.
Tottenham and Manchester United target Sessegnon, 17, is with the Young Lions for the first time for games against Romania and Ukraine, having been considered for the senior side.
Boothroyd said: "There's a right time and a right place to see if he can maintain what he's doing.
"There are a lot of pitfalls on the way. So I think he's best to be judged at the end of his career, when he's got 200 caps and everything else.
"He's got a long way to go yet. He's not ready for them yet. He's in exactly the right place at the right time for his club, playing plenty of games and getting plenty of experience for his country.
"It was a really quick discussion (about senior selection).
"When there is attention on someone who is doing so well there is inevitably going to comparison with the Wayne Rooneys and Michael Owens and the rest of it.
"But he's clearly got something that is special and it's about making sure we keep his feet on the ground and not get too excited, make sure he doesn't get too excited — which I'm sure he won't — and we just progress him at the right pace."