Smith is facing a fortnight on the sidelines after suffering a hamstring injury against Nottingham Forest last week and fellow winger Ephraim serves the final game of a three-match ban.
But midfielder Akos Buzsaky made his comeback from four months out with a knee injury as a late substitute at Preston on Saturday and should be involved again.
Boss Neil Warnock is unlikely to make many changes despite Rangers being held to a 1-1 draw by the bottom club although Fitz Hall, Pascal Chimbonda and Rob Hulse are options.
Defender Peter Ramage (cruciate) and strikers Jamie Mackie and Patrick Agyemang (both broken leg) remain long-term absentees.
Source: PA
Source: PA