David James has admitted that he failed to prepare properly for his second-half outing against Denmark.
The Manchester City keeper conceded all four goals in England's 4-1 humbling in Copenhagen on Wednesday, although he was not at fault for all of them.
James, 35, said: "Because I knew I wasn't going to start I did not do my starting preparations - but you should always prepare to play.
"I did not adhere to that and everyone saw the results."
James did nothing to dispel the 'calamity James' tag that has haunted him, with a rash error of judgement for Denmark's first goal.
FAMOUS ENGLAND SLIP-UPS
USA 1-0 England - World Cup 1950
England 0-0 Saudi Arabia - Friendly 1998
England 2-2 Macedonia - World Cup qualifier 2002
USA 2-0 England - Friendly 1993
England 1-3 Australia - Friendly 2003
It triggered a spell of three goals in seven minutes that left England reeling.
When the fourth goal went in, James became the keeper at the centre of England's biggest defeat in 25 years.
A contrite James added: "The whole thing about preparation is that you could go on in the first minute.
"It is a lesson I try to teach youngsters and it is one I should follow through myself.
"Maybe I can get away with this one because it is a friendly and has no bearing on qualification.
"But I am representing England and I should have paid more attention. There were things I did that I will make totally sure I never do again."
James has lost his place as England's number one to Tottenham's Paul Robinson, largely on the back of a blunder nearly a year ago that allowed Austria to salvage a draw from the opening World Cup qualifier.
He will now find Norwich keeper Robert Green breathing down his neck for the deputy's spot.