The Scotland international forward, who has been heavily linked with a move away from the Cardiff City Stadium this summer, will almost certainly remain put for the time being at least having sustained a hamstring injury at the weekend.
McCormack was taken off in the 36th minute at Blackpool and now looks set for a lengthy period of rehabilitation.
Paul Quinn (knee) and Mark Kennedy (calf) will also miss out but look set to return in time for Sunday's clash with Bristol City, yet fellow full-back Kevin McNaughton (ankle) remains four or five weeks away from full fitness.
Midfielders Joe Ledley and Chris Burke have struggled of late with illness but are expected to be okay as is Stephen McPhail (hamstring) who also picked up a knock at Bloomfield Road and Gabor Gyepes (knee).
