LONDON - 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 that Ferdinand was not currently in contention to passengers on an underground train a day before he formally announced his squad.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 told reporters."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.