“Sometimes there is a tendency to overdo things to make up for it. As we all know in this game it is played in the top two inches.
“We all have to find a way to ensure that we feel prepared physically, technically and we are ready for the battle, but also to make sure we are fresh and make sure we can make those decisions in the heat of the games.”
McCullum added to Australia’s Channel 7: “I actually feel like we over-prepared, to be honest ... I think the boys just need a few days off and we probably need to change up a few of the training methods.”
England’s players are now set to be handed four days off in the holiday resort of Noosa before the third test in Adelaide begins on December 16.
After travelling to Australia with high hopes of reclaiming the urn with a first Ashes series win since 2010/11, England are staring down the barrel of another embarrassment after just six days in the field.
England have never come from 2-0 down to beat Australia, who have not lost three consecutive home tests to anyone in 38 years.
However, they did come from 2-0 down to tie the last series between the sides 2-2 on home soil two years ago.
“We’ve been here before and we’ll have to make sure we stay tight as a group and iron out a couple of the chinks we’ve shown over the last two test matches,” McCullum said.
“It’s very hard to beat Australia at home if you’re going to be deficient in all three areas. We’ve got some work to do. There’s no point feeling sorry for yourself, you pick yourself up and you go again.”