Duo sidelined due to knee and Achilles problems respectively
Flynn Downes could be out of action for two months after sustaining a knee injury against MK Dons at the weekend.
Stephen Ward also picked up an Achilles injury in Town's 1-1 draw at Stadium MK on Saturday.
"Flynn's is a bad one," Paul Lambert said.
"He'll be out for a couple of months but we've got to get on with it.
"He shouldn't need surgery but he'll certainly be out for a while.
"Wardy is the same, he'll miss the game this weekend. Hopefully he'll be back pretty quickly, though."