Rio Ferdinand and Jonny Evans will both miss Saturday's Manchester derby at Old Trafford.
Ferdinand has not recovered from the calf injury he sustained in the warm-up ahead of Manchester United's shock defeat at Wolves last week.
Evans played in that game but missed Northern Ireland's hammering by Scotland on Wednesday with an ankle injury and is still sidelined.
"Rio Ferdinand got a calf injury last week. He will be out for a couple of weeks," confirmed Sir Alex Ferguson.
"Jonny Evans was injured in training with Northern Ireland. He is out so Chris Smalling will play. I am sure he will do well."
