London, Nov 19 Manchester United centre back Rio Ferdinand will not be able to play again this year and has been informed that he needs another six weeks of rest and physio work before his back will be strong enough for Premier League football.

Ferdinand, 31, had been playing with back problems since last season, leading to a calf injury this term.After a series of poor displays he decided to get the problem sorted out for good.

Rio had hoped to be back by the start of December, but by the time he plays again, he will have missed at least 15 matches, The Sun reports.

One theory being looked into now is that he might need his hip realigned. If the hip is slightly out it will lead to strain on other parts of the body, including his back.

Ferdinand's last game for United came in the 2-0 defeat at Liverpool on October 25 when he was out-run and out-muscled by Fernando Torres for the opening goal. (ANI)