The Daily Mail says Ferdinand reported to United's Carrington complex on Monday but went for a scan instead of training.
The England centre half fears a recurrence of a groin problem that forced him to miss four of United's final six games in the run-in to regaining the title last season.
Coming on the day when it was also revealed midfielder Paul Scholes will be ruled out until February, it was hardly the news manager Sir Alex Ferguson needed before the clash with rival Arsene Wenger and his Premier League leaders.
Ferdinand was replaced by Gerard Pique 20 minutes from the end of Saturday's convincing 4-1 win over Middlesbrough, a victory that lifted United to the top until Arsenal took a point from Liverpool on Sunday.
United insiders expect Ferdinand to bite the bullet for Saturday's crucial lunchtime showdown at the Emirates, which is likely to be one of a handful of matches this season that settle the destination of the title.
But there is concern that Ferdinand's injury will have to be addressed in the long term if it keeps returning to bother the defender, who is 29 next month.