Ephraim has completed a three-match ban for his red card at Reading earlier this month and will probably be on the bench.
Fellow winger Smith has yet to recover from the hamstring injury he sustained against Nottingham Forest a fortnight ago, although boss Neil Warnock hopes he will be back to face Leicester next weekend.
Danny Shittu and Fitz Hall look set to keep their places in central defence after replacing Matt Connolly and Kaspars Gorkss against Ipswich in midweek and helping the leaders to a 2-0 win.
Fellow defender Peter Ramage (cruciate) and strikers Patrick Agyemang and Jamie Mackie (both broken leg) are long-term absentees.
Source: PA
Source: PA