Four of them are defenders, Anthony McMahon, Matthew Bates, Andrew Taylor and David Wheater. The other two are James Morrison (who impressed on Saturday in his few minutes on the pitch as a substitute) and Anthony Peacock, both are midfielders.
Boro have three players certainly out (Reiziger, Ehiogu and Davies). Cooper is likely to be rested so he his fit to play at Old Trafford at the weekend and five more are very doubtful (Hasselbaink, Viduka, Job, Parlour and Riggott).