King is doubtful due to a knock picked up in last weekend's last-gasp 1-1 draw at Charlton as Blues made it seven points from a possible nine in their last three games.
Meanwhile, towering Serbian striker Zigic has been dropped from manager Lee Clark's matchday squad in advance of the match following his unsatisfactory training this week.
Clark has been angered by Zigic's poor work ethic and attitude during sessions at the club's Wast Hills training base.
Deadline-day loan signing Wes Thomas will be champing at the bit for a recall as he looks to prove his worth, as will the likes of Nathan Redmond, Peter Lovenkrands and Hayden Mullins.
Darren Ambrose, David Murphy, Stephen Carr and Will Packwood remain sidelined due to injury.