England boss Brian Ashton says he knows just five of his World Cup starting XV with only three games to go before the tournament starts in September.
Ashton is all too aware he is not in an ideal situation
He said: "Probably about five of the starting XV are definite, which is not how it should be at this stage of 2007.
"In other positions, it's a question of deciding which of two players will make the XV. We don't have 10 complete blanks. We've got five and 20 others."
Ashton names a 40-man training squad for the World Cup defence on 13 June.
Many of the squad which has twice been thrashed by South Africa are likely to miss out as the big guns from Leicester, Wasps and Bath reappear after their break from international duty.
It was always going to be a tough tour but we have learnt so much from this trip - probably more than the South Africans
England fly-half Jonny Wilkinson
England, who meet the Springboks in Paris on 14 September in a World Cup pool match, have warm-up games against Wales and France, twice.
"We have got to be able to match South Africa physically," said Ashton, whose side face the USA in their opening World Cup match on 8 September.
"Certainly, we can't afford to go on the field playing South Africa in the World Cup with half a team that physically is going to be outmatched, and conditioning work is an integral part of our preparation.
"In terms of the warm-up games, I think it is quite important we get the combinations we want on the field against America to play together as often as possible before then.
England begin their World Cup preparations on 25 June when they meet up to prepare for a 12-day training camp in Portugal.
Jonny Wilkinson, who captained the side in the 55-22 hammering in the second Test against the Boks, cannot wait to fly back from South Africa and start preparing for the World Cup.
"Some harsh lessons were learnt, and I hope they will stand us in good stead," he said.
"What matters now is the next three months. The World Cup warm-up period is brilliant because we can get so much done during that time.
"It was always going to be a tough tour, but we have learnt so much from this trip, probably more than the South Africans.
"Without this trip, we may not have known exactly what we had to work on or the players who could make an impact."