A traditional strength of England teams, the centre back position has suddenly become a nagging worry for manager Roy Hodgson.
Following the retirement of John Terry, Hodgson's latest England squad for the World Cup qualifiers against San Marino and Poland reflected his continued desire to look to the future.
That meant no recall for 33-year-old Rio Ferdinand even if central defence is an area where Hodgson feels England are currently under-strength.
The England coach is keen to stress that the door is not closed on Ferdinand's England career, but he will only be called upon if needed and will not be treated as a utility squad player.
Whether or the 81-times capped defender will be keen to return to the fold is another matter after the England coach apologised for revealing to passengers on an underground train a day before he formally announced his squad, that Ferdinand was not currently in contention.
A report in British tabloid the Daily Mirror suggested Hodgson had gone further and told passengers Ferdinand's England career was finished.
"I am very disappointed that I was travelling on a tube train and apparently suggested that Rio's career is over," Hodgson said.
"I have not got anybody to blame but myself. All I can say is that I have no intention of closing the door on Rio Ferdinand," he added.
"He certainly deserves an apology from me. I am disappointed he had to find out that he had been excluded from the squad in that way. I respect the man and I respect the player."
In the absence of the Manchester United defender, England are relying on Chelsea's Gary Cahill, Everton's Phil Jagielka, Manchester City's Joleon Lescott and uncapped Ryan Shawcross from Stoke City, all of whom could be accused of lacking the aura of authority possessed by past England centre backs.
The visit of one of world football's whipping boys San Marino on October 12 should prove relatively trouble-free but a trip to joint Group H leaders Poland four days later will be a stern test for a defence shorn of an influential leader.
Hodgson says he is in stage one of a rebuilding process he hopes will end up with England in contention at the World Cup in two years time.
It is in that vein that he is looking forward to the return of Manchester United's injured duo Chris Smalling, 22, and Phil Jones, 20.
"I think it is an area that will get stronger. First of all we have got (midfielder Michael) Carrick who is more than capable of going back there.
"We believe that there are two very interesting centre halves in Jones and Smalling both of whom have not been available to us so I think our current plight, if it is a plight, is one that could rapidly change by next March."
Hodgson is not envisaging a U-turn from Chelsea's Terry who called time on his international career four days before he was found guilty of racially abusing Ferdinand's brother Anton by an FA tribunal. He had already been acquitted in a court of law.
"I regret his decision of course," Hodgson said.
"He did a great job playing under me.
"He has made his decision and it is a decision that is irrevocable as far as he is concerned and all I can do now is wish him well in his Chelsea career.
"It has got to be a closed chapter as far as I am concerned."
Photograph: Shaun Botterill/Getty Images