Wise said: "I'm not going to shut the door completely. Maybe he's got his mind set on something else. I'll speak to him when he gets back on the 20th.
"I asked Shaun to come back and he decided that he wanted to stay at Crystal Palace. I tried to cut the loan short, and it was a mistake on our part that we didn't have a recall (clause).
"But all Shaun had to do was sign a release form himself, get our club to sign a release form, pop in and see Neil Warnock and say he wanted to go back. I'm sure Crystal Palace would have let him come back to us.
"But I spoke to him and he decided that he didn't want to sign the release form, and that he wanted to honour his contract at Crystal Palace.
"I said 'hold on a second, you've got 18 months here and 19 days there. What are you saying to me?' Basically they don't even pay half of his money.
"I'd have liked him to come back and I would have liked him to play the other day. But what happens to him now is that he comes back on the 20th unless Crystal Palace buy him. Maybe that's what he's hoping."