The Cameroon international spent the second half of last season on loan at Fulham, and Martin Jol was believed to be mulling over a permanent deal.
No agreement has been reached, though, and Enoh is now considering other offers.
Premier League new boys Palace remain in the market for fresh faces, with Ian Holloway eager to bring in top level experience.
He could, however, be set to miss out on another target, in a frustrating summer for the Eagles boss, with Enoh admitting that the UEFA Champions League football on offer at Olympiakos would make the Greek outfit his preferred choice.
The 27-year-old told De Telegraaf: "It's a good option. Olympiakos will participate in the Champions League and are a big club in Greece. My agent is in talks with them.
"Crystal Palace have also made contact. I am honoured by their interest, but first I will talk with Olympiakos."