Sir Clive Woodward has admitted that England's standards have slipped since their World Cup triumph in Australia.
But Woodward has vowed that a different England will emerge against Wales following a below-par display against Ireland.
Head coach Woodward promised he would not over-react in the wake of his RBS 6 Nations and world champions 19-13 home defeat, which ended a run of 22 successive Test wins at Twickenham and destroyed Englands Grand Slam dream.
A performance like the one against Ireland was waiting to happen, and I am glad it has happened sooner rather than later, said Woodward.
It has been a massive wake-up call for everyone in the squad, from me downwards.
We can take it playing badly one week, but we cant afford to do it ever again.
Everybody in the squad fully understands why we won the World Cup and why were the number one-ranked team in the world, and how easy it is to let it slip.
I pride myself on England being the best prepared team and setting standards above any other team.
I think theyve slipped after the World Cup, through nobodys fault, but everybody has got to take responsibility for this, especially me.
Were now back together again, and have had the wake-up call, but I will just repeat - Ireland deserved to win.
I think history will look back on this and say its an important lesson the players had to learn.
When you see the side weve got out, if we can get it right between the ears, then Ive got no doubt we can move on to be a lot stronger and better team, even than during the World Cup.