Do United or Rio and Vidic Need To Worry?

Reports today suggest that both Nemanja Vidic and Rio Ferdinand are both doubtful for Saturday's match at home to Blackburn Rovers, presumably meaning we will have to rely on Jonny Evans and Wes Brown to play in the centre of our defence.

Both Vidic and Rio have been criticised for their recent form, particularly in light of the Liverpool game, when Rio was out-muscled and out-run by Fernando Torres, and Vidic was sent off for his third game in the row.