Rob Andrew has questioned whether England's World Cup squad are ready to hit their peak.
But the Rugby Football Union chief insists he is not ruling the host nation out of contention for the tournament, which starts in two weeks' time.
Stuart Lancaster's squad features a number of players relatively new to international rugby, with the midfield and wing areas showing particular inexperience - all the more so if recent rugby league convert Sam Burgess earns a starting spot.
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"Is this team going to peak at this World Cup? I don't know. I doubt it, to be honest," Andrew, professional rugby director for the RFU, told the Telegraph.
"I suspect this team will get better over the next two or three years. I don't think there's any question of that, because the age profile and the experience profile is going to grow.
"That doesn't mean, today, it's not going to be good enough, or have the experience to win this World Cup. World Cups are about momentum and letting it grow."
There are a number of experienced players involved, with forwards Dan Cole and James Haskell and scrum-half Danny Care boasting over a half-century of caps apiece and Care's fellow number nine Ben Youngs in line to join them during the tournament.
And Andrew believes even the younger members of the 31-man group are battle-hardened enough to play their part to the full.
"They've gained significant experience over the last three years," he said.
"They've beaten New Zealand, they've beaten Australia, drawn with South Africa in South Africa, been to Cardiff and won, been to Cardiff and lost pretty heavily, been to Dublin and won, been to Dublin and lost.
"They've got a fair few scars on the way through. Every team has that. We all make mistakes. The key is not to repeat them."