Neither striker Jutkiewicz (quad) or midfielder Gardner (knee) figured in any of Blues' pre-season games.
But the injuries are only judged to be minor and Karanka anticipates that they will soon be back action.
"We are not in a hurry (to get them back)," said Blues' Head Coach.
"I don't want to risk one or both of them and then lose them for four or five weeks.
"I prefer to keep them out until they are 100 per cent and they can help and support the team, rather than risk them for the game on Saturday.
"They are doing really well and when the Medical Department thinks it is a good time for them, they will start with us."
Meanwhile, the only other player definitely sidelined is midfielder Josh McEachran, who has not featured since February after tearing his ACL.