The Norwegian striker suffered ankle ligament damage while on international duty and looked to be over the problem when he made a goalscoring return in the 6-0 Worthington Cup rout of Bolton, but suffered the setback in training the following week.
Iversen is likely to lead the attack alongside Yannick Kamanan while Leonhardsen could come into the midfield.
Goran Bunjevcevic will get another run-out in defence after coming through 45 minutes of the reserves 2-1 defeat to Southampton on Monday night, while Neil Sullivan, who has been rested from first-team duty, could also get a game between the posts.