Kevin Pietersen insists England must simply forget about their trouncing in Perth as they begin their preparations for the fourth Ashes Test on Boxing Day.

Pietersen himself could muster only three runs in two innings - after his career-best 227 in the preceding landslide victory in Adelaide - and he is as keen as anyone to put the WACA behind him.

"The key to us being successful on this Ashes trip would just be to forget about last week - learn from the mistakes we made, but just forget about last week," he said.

He was one of three frontline England batsmen to fall lbw to Mitchell Johnson, for nine runs between them, in a first-innings collapse which handed the initiative to Australia.

England must therefore begin at the MCG level in the series again, at 1-1 with two to play.

Pietersen reports England came to the conclusion, immediately after their 267-run setback in Perth, that they must leave that experience in the past if they are to retain the urn after all.

He added: "The open and honest meeting we had the evening the game finished was a very good meeting.

"We have left that, and it's time to look forward now.

"We've got to learn from the mistakes we made - and we'll be better prepared come Sunday."