At the end of the day its up to the players owner to decide! no one else, you cant go bulling managers into selling their players lol.
The negotiations idea is a complete waste!, far to exspensive and the bidder can be taken for a ride!, there must be a better idea for doing this, e,g, there should be a section in every managers account where they can choose which players to put in it or the auction or a space next to the player in the squad where you can tick or put a colour dot next to it so to inform other managers this/these players are up for negotiations!. Nordeus takes a far too high percentage out of it at the present time!, I never use it! you might as well save for a scout or go on the ordinary auction.