Aaron Wan-Bissaka has not played since starting the 2-2 draw against Tottenham at the back end of last month.
It was initially thought that the fullback would be back in contention to play last weekend.
However, before the 2-1 victory over Luton, ten Hag revealed that Wan-Bissaka had sustained another injury in training.
The 26-year-old is set to be out for at least three to four weeks.
