"It is not a definite but I am optimistic," said Coleman to the CT.
On the delay, Coleman said: "When you loan players, especially from the Premier League, it is not just straightforward saying he's going to come to us and this is what he earns and he's here for this or that amount of time.
"There are other little things in the contract that are written in and you have to agree to to get him, and that's what has been the hold-up."
Cardiff City are been reported as being interested and there were rumours circulating arpund the Welsh Capital yesterday that Vokes was in talks with the Bluebirds.
Chris Coleman said "It wouldn't surprise me because it has gone on for a couple of weeks. "Ultimately, if all the clubs agree it will be down to the player and there is nothing more I can do, but I am still hoping he will come here."