Lewis Moody will miss England's Rugby World Cup opener against Argentina on Saturday after failing to recover from a knee injury in time.
The England captain suffered medial ligament damage in the warm-up victory over Wales on August 6 and had been due to make a full return to training in Dunedin today.
But England manager Martin Johnson made the early call to rule his skipper out of the match on the advice of team medics.
"Lewis won't play at the weekend. He is not quite ready to go today. We hoped he would be fit to start training but he is not quite there," said Johnson.
"It is quite a simple decision at the minute to hold him back another week.
"The medics and the fitness guys take him through a progression of training and we hoped it would all be ready to go today but he is just a little bit short."
Mike Tindall captained England in Moody's absence through the Six Nations and in their last two warm-up games, against Wales away and Ireland at the Aviva Stadium.
James Haskell enjoyed an impressive Six Nations at openside and he is the obvious choice to start in the number seven jersey against Argentina.
Johnson, who will confirm his line-up to face Argentina on Thursday, insisted Moody still has a significant role to play for England at the World Cup.
"We are very happy with the other guys so it is a very simple decision to hold him back another week," said Johnson.
"It is the opening game of what hopefully is a long tournament so you can force these things sometimes and that can go either way.
"He has been running around today so he is not a million miles away.
"It is just one of those calls, 'are you ready to participate fully this week and play a Test match this Saturday?' Not quite."
Moody first injured his right knee in January playing for Bath, which ruled him out of England's Six Nations title-winning campaign.
The veteran flanker suffered the recurrence when Tom Palmer fell on him at a lineout, 62 minutes into the warm-up win over Wales at Twickenham.
Moody immediately feared for his World Cup place but the heavy strapping he was wearing saved him from more serious damage - and as recently as Thursday he felt "on the right path".