Both players were withdrawn during the second half of the 1-0 win over Brighton on Tuesday night as City maintained their 100% home record in the Championship to remain top of the table.
"Ritchie came off with a tight chest. He will be assessed but hopefully he will be okay," said manager Nigel Pearson.
"Nugent got a knock on his Achilles and we had Jamie Vardy on the bench, so we thought it was prudent to take him off at that point. There is no point running a player into the ground."
Defender Sean St Ledger is still recovering from a hamstring injury and will not be involved.
Wilfried Zaha and Dean Moxey are both available for Palace.
Both players sat out Tuesday night's 1-1 draw at Barnsley in order to serve one-match suspensions, but are expected to be recalled at the expense of Jonathan Parr and Andre Moritz, who started in their stead at Oakwell.
Bolton-bound Dougie Freedman had departed as manager just hours before the match in South Yorkshire, and Lennie Lawrence and Curtis Fleming, the men who took temporary charge, are both expected to eventually follow Freedman to the Reebok Stadium.
Defender Darcy Blake recovered sufficiently from injury to take a place among the substitutes on Tuesday, but his hopes for a place in the starting line-up may be dashed by Joel Ward, who got the nod at right-back and performed well.
There are no new injury or suspension worries for Palace, although defender Paddy McCarthy remains unavailable with the groin problem that has prevented him from making an appearance this season.