Rio Ferdinand will have a scan on his back injury on Monday.
Manchester United manager Sir Alex Ferguson confirmed the news ahead of the Barclays Premier League clash with Chelsea at Old Trafford.
On Friday, Ferguson claimed Ferdinand would be fit but once again he has been ruled out after suffering further back spasms and Jonny Evans was selected instead to partner Nemanja Vidic in the centre of United's defence.
"We are sending him for another scan because we want to get to the bottom of the problem," Ferguson told Sky Sports.
Ferdinand has not figured for the Red Devils since their victorious Club World Cup campaign in Japan last month.
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