John has been missing since suffering a dislocated elbow on the opening day of the season and on-loan West Ham youngster Sears has been sidelined since spraining his ankle against Scunthorpe last month.
Davis is still waiting to make his second Eagles debut after a hamstring injury and a virus.
All three resumed full training over the international break and should be involved in some capacity, although with Palace having won three and drawn one of their last four matches, Neil Warnock has no need to rush them.
Jose Fonte should also return after illness but Victor Moses is doubtful with a thigh injury.
