For what it is worth, my reading of the situation is this.
Pan has come to the end of another season and because of his slight lack of English understanding, he is relying on his agent to give him advice.
His agent is probably saying that he might be able to get a better deal than the contract that Argyle are offering him if he does his work and is able to get another Club interested in him.
Rumour has it that Wednesday were interested and that Argyle turned down any interest by saying that it would not be in Argyle's interest to sell him to another div 1 club.
This is restricting the Agent from touting Pan so far, but as Pan was injured at the end of last season, that fact alone may be putting clubs off at the moment, as there would be no proof that he has recovered during the break until pre-season is completed.
Pan should return for pre-season and other clubs will probably keep an eye on how his injury/pre-season turns out.
I believe that Wednesday have gone elsewhere for a midfielder, but they are having a clear-out anyway and may be interested in Pan later in the season (window closes after the start of the season, usually end of August) if Pan doesn't go up to the Championship, and if Argyle drop their position of not wanting him to go to an opponent in div 1.
I'm not sure that speculation about whether Pan will go or not has any grounding at the moment as any Club wanting to buy him would want to make sure that he would be fit and available before informing Argyle that they were interested in purchasing him, so he may even start the season with us before any further transfer interest comes about.
As soon as a hint of a sale becomes open knowledge, it is usual that the player is withdrawn from games in order that he does not get injured before negotiations come to a conclusion, so there may be more interest from us fans later on in the season.
Of course, if Pan signs the contract with Argyle then he will come off the transfer list, but that in itself would not prevent him from being sold, except that compensation would be allied with his extended contract term.