United centre-back Ferdinand's long-term back injury has flared up again, says The Sun.
Ferdinand, 33, felt a pull in training on Thursday.
He complained of pain after a routine challenge. Ferdinand was quickly sent for a scan which revealed it was the same trouble which has dogged him in recent seasons.
Ferdinand has a problem at the base of his back, leaving him in agony and struggling for mobility.
He missed yesterday's session at United's Carrington base.