The Jamaican defender, who spent the back end of last season on loan at Selhurst Park, finally sealed his permanent switch from Derby on transfer deadline day.
Davis could go straight into the back line as Paddy McCarthy is suspended following his red card at Peterborough last time out, although veteran centre-half Matt Lawrence provides another option.
The Eagles are still without strikers Stern John (elbow) and Calvin Andrew (knee) so Freddie Sears and Alan Lee will continue in attack.
Teenage winger Victor Moses was restricted to a place on the bench against Posh after a knee injury and could return to the starting line-up.
Defenders Rob Jones and Niall Canavan return to the squad for Scunthorpe's game at Crystal Palace.
Jones, a club-record signing from Hibernian this summer, missed the Iron's last two games after being concussed in the 4-0 thrashing at Sheffield Wednesday but the centre-half is available to face the Eagles.
Teenage central defender Canavan missed the defeat against QPR two weeks ago due to an ankle injury, but he is also back in contention.
Canavan came through 90 minutes of a reserve team game against Middlesbrough on Tuesday night and could start after an impressive display in the Carling Cup win at Swansea.
Josh Wright and Grant McCann are pushing for starting berths after being on the bench against the R's
Andrew Wright (broken metatarsal) will definitely not feature, and fellow defender Kenny Milne is still not ready to return as he continues to work his way back from a knee injury that has kept him out for 13 months.