England captain Alastair Cook described Tuesday's Ashes loss as the lowest point of his career, but rejected suggestions his team's flaccid defence was a sign it was in terminal decline.
The tourists went into the series as firm favourites after their 3-0 victory in the series in England earlier this year.
But even Cook conceded they were completely outplayed in the first two Tests in Brisbane and Adelaide, and again in Perth -- where they lost by 150 runs to give the home side an unbeatable 3-0 lead with two Tests left to play.
A feature of the series has been the poor performance of senior English players, including Cook himself, powerful batsman Kevin Pietersen, wicketkeeper-batsman Matt Prior, spinner Graeme Swann and swing bowler Jimmy Anderson.
Cook, who suffered his first series defeat as skipper, told reporters he realised there would be a detailed autopsy of the team's failure.
He accepted that key England players were down on their best form in the first three Tests, but said it was premature to read anything more long-term into it.
"I wouldn't necessarily say that," he said when asked whether the loss signalled an English team in decline.
"What I would say is, unfortunately, when we needed people to be in form and playing well, we haven't done that, and that's why we lost.
"We haven't done ourselves justice out there in these three games, people haven't performed like we know they could have done, and it's frustrating when that happens."
Cook pointed to the Australians, with veterans like Brad Haddin and Mitchell Johnson playing some of the best cricket of their careers, as evidence that form can be turned around by experienced players.
"You only have to look at the Australian side, there's a few guys on the back end of 30 delivering a huge amount of success for Australia," he said.
"The simple fact of the matter is we haven't had enough players in form with either bat or ball," he added.
"You can't put it any more honest than that, and people in the dressing room know that.
"It hurts like hell when you come into a contest and you end up being second best."
Cook answered "Yes" when asked if the Ashes defeat was the lowest moment of his career but did not elaborate.
But he said the English would not be pushed into making wholesale changes for the last two Tests in Sydney and Melbourne.
"I think for this tour we'll do what we always do -- try to pick the side and try to prepare the side which we think is the best side to win the next game," he said.
"When the game's just finished and everyone's really emotive and it's hurting like it's hurting, you could make some very radical decisions which could be the wrong ones.
"These have to be very cool, calculated decisions at the right time."
Cook said there was always pressure on England players to deliver due to the depth of talent in domestic cricket.
Proof of this, he said, lay in youngster Ben Stokes, who was called into the team for the second Test and scored his maiden Test century in the third.
Cook conceded his own form had been below-par, but refused to blame the extra pressure of captaincy.
He also backed Andy Flower to continue as the team's coach.