Davis picked up his fifth booking of the season in the Boxing Day win over Ipswich and sat out the 0-0 draw with Swansea but is expected to return to the starting line-up at Hillsborough.
Right-back Danny Butterfield could be back in the side following a hamstring injury while Clint Hill is expected to return to left-back with Lee Mills missing out.
The Eagles will be without striker Freddie Sears after he was recalled from his loan by parent club West Ham.
Goalkeeper Darryl Flahavan has returned to Selhurst Park following his loan spell with Oldham.
The 31-year-old suffered a blow to the face and X-rays have revealed he suffered a fractured cheekbone which requires surgery.
Sheffield Wednesday look set to be without Richard Hinds - and possibly several other players.
Hinds, restricted to nine appearances this season, is struggling with a heel problem while midfielder Michael Gray, goalkeeper Lee Grant and Tommy Spurr have all been feeling unwell.
Grant has been unable to train all week but caretaker-manager Sean McAuley is hoping the trio will be available for the third-round tie at Hillsborough.
Leon Clarke is expected to partner Marcus Tudgay up front following Luke Varney's return to parent club Derby while Frank Simek and Tom Soares, on loan from Stoke, will be hoping to retain their places in the starting line-up.
Wednesday's scheduled league clash at Blackpool on Monday fell foul of the weather.