Striker Nicky Maynard, winger Jamal Campbell-Ryce and midfielder Danny Haynes all remain in the treatment room after missing Tuesday's defeat at Watford.
Maynard has a dead leg, Campbell-Ryce is nursing a calf problem and Haynes is unwell.
Jamie McCallister sustained a calf injury at Vicarage Road and he will not travel north, while Johnson has revealed that another unnamed player has come down with an illness.
Jamie McCombe and Brian Wilson remain long-term absentees so Johnson may be forced to scour the loan market ahead of the clash.
"We find ourselves a little short for Saturday," Johnson told the club's official website.
"I'll have to ring around a few clubs and speak to the chairman to see if there's anything we can do to fix that."