Ridgewell was forced to sit out Blues' last two matches with a virus but has returned to training again this week and is expected to go straight back into the centre of defence for the live television game at Deepdale on Saturday evening.
Franck Queudrue also had a virus which forced him to be substituted in the 1-0 away win at Plymouth on Tuesday night and has not trained since.
However, the French left-back is expected to have recovered in time to make the squad that travel to Preston.