Martin O'Neill says the young players in his Republic of Ireland squad "have come of age" during their Euro 2016 campaign.
Ireland exited the European Championship in the round of 16 on Sunday, giving up an early lead to lose 2-1 to hosts France.
Despite being outclassed in the second half at Stade de Lyon, O'Neill had no interest in suggestions the team would have been out of place had they progressed against the odds.
"I don't think there's any good time to go out of the competition" he said.
"We were playing possibly the favourites. We had them under severe pressure. We were feeling we could win the match.
"When I analyse the qualification and the group we were put into, I think the team has done fantastically well. Hence my disappointment," he added, Ireland having drawn with Sweden, lost to Belgium and beaten Italy in the pool stage.
According to O'Neill, the introduction of Kingsley Coman at the break indicated the quality of opposition Ireland were up against, as he looks ahead to the qualifying campaign for the 2018 World Cup.
"A substitute came on who plays for Bayern Munich," he said.
"They have very fine players. Putting heart and soul into the game has become a prerequisite for us. Our young players have come of age. It's up to them to take it further.
"It's still an achievement, but it's not something we want to rest on."