Clarke has missed the last fortnight under doctor's orders following concussion, while Danns was not given permission to play in Tuesday night's fourth-round replay win at parent club Leicester.
Defender Joel Lynch missed out on Tuesday night due to a tight hamstring and remains doubtful, but goalkeeper Alex Smithies is expected to return to the side following a family bereavement.
Right-back Jack Hunt, midfielder Oliver Norwood and striker James Vaughan, all rested by starting on the substitutes' bench in midweek, will also return to contention.
But midfielders Danny Ward (foot) and Keith Southern (Achilles), plus strikers Lee Novak (foot) and Jermaine Beckford (hamstring) remain sidelined.
- Sports & Recreation
- Alex Smithies
- Joel Lynch