The injury will be assessed later this week before full extent of the injury is known.
Stuart Parnaby missed yesterdays game with a groin problem. The full back has been put on antibiotiics after a wound in his groin became infected.
There was good news last week when Ugo Ehiogu managed three quarters of the Reserves game against Manchester United. His services will be reuired in the coming weeks.
Ray Parlour (knee), Stewart Downing (knee) and Tony McMahon (shoulder) remain as Boro's long term injury casualties, Malcolm Christie (leg) is expected to return in the next couple of weeks.