Michael Owen says it could be a decade before England have as good a chance of winning a major tournament as they do at Euro 2004 and the 2006 World Cup.
Striker Owen believes the number of players in their mid to late 20s, plus the promising youngsters coming through, have placed Sven-Goran Eriksson's squad in an ideal position.
"Now that we are in our prime, these next two tournaments will be the acid tests," Owen told reporters at England's training camp outside Lisbon on Tuesday.
"They're such a good group of players that we might not have as good a chance in the next five or 10 years as we have in these next two tournaments."
England's Euro 2004 campaign opens on Sunday against holders France and continues against Switzerland and Croatia.
"We've got a good base of regulars, some young flair and some older experienced players. We've just a great blend at the moment," Owen said.
"It's fair to say that the next two years are massively important for quite a number of players in the squad."
Captain David Beckham, defenders Sol Campbell and Gary Neville, and playmaker Paul Scholes are 29 while Owen and midfielder Steven Gerrard are in their mid 20s.
"The beauty of it in some respects is that things like World Cup and European championship medals are so special because they're few and far between.
"But I would be disappointed if the bulk of this squad didn't win a major trophy," Owen said.
Quarter-finalists at the 2002 World Cup with much of the current squad, England have only one major tournament victory to their credit, the 1966 World Cup.
They have lost only one competitive match under coach Sven Goran Eriksson, the quarter-final against eventual champions Brazil at the 2002 World Cup.