Sir Clive Woodward told Sky Sports that England must generate more creativity in their backline if they are to compete for rugby's top honours.
Stuart Lancaster's men were unable to replicate their 2012 victory over New Zealand at Twickenham on Saturday, slipping to a 30-22 defeat to the reigning World Cup champions, albeit in valiant fashion.
Wasps lock Joe Launchbury scored the hosts' solitary try but Woodward - who led England to World Cup glory in Australia a decade ago - thinks Lancaster's backs must start crossing the whitewash more often.
And the former Leicester player says the 2014 Six Nations will be crucial to England's development as they aim to construct a side capable of collecting the World Cup crown on home soil in two years' time.
"England have got a forward pack that needs to be respected throughout the world and the bench looks very strong," said Woodward, after watching the New Zealand clash in the Sky Sports studio.
"But I just don't think we have learnt enough about the backline and with two years out they need to have a re-think about who's playing in various positions."
"The plusses far outweigh the minuses after this great performance but we got outscored by three tries to one.
"So in the Six Nations they have got to take the bull by the horns and try to find a back division that is scary and can go head-to head with New Zealand's.
"They need to build a team that can go for 80 minutes and put a real emphasis on scoring tries as I don't think you can get to number one or win a World Cup without that - and it is both a personnel and mind-set thing.
"Stuart has the individuals but the art of being head coach of a national team is selection so he needs to pick players who he thinks can handle the step up and take risks, and then decide how he wants to play the game which, for me, is a little bit quicker."
Ex-All Black hooker Sean Fitzpatrick credited his nation for overcoming a resolute England and not falling to a second consecutive reverse at Twickenham, following last autumn's 38-21 loss.
The 50-year-old also praised 100-cap Dan Carter - but believes New Zealand would be able to cope without the stalwart fly-half should he not figure prominently over the coming years.
"New Zealand were not at their best but they will be very happy with the win," said Fitzpatrick.
"It was a hard day at the office and England played very well - albeit without creating enough scoring opportunities - but this All Blacks side is better than 12 months ago.
"Carter has been such a servant to New Zealand rugby and hopefully he can push on towards 2015, but if he is not there, there are others who can come in like Aaron Cruden and Beauden Barrett."