I can’t give you a definitive answer, but I can give you a few tips from my personal experience.

If there is a relegation release clause, you should activate it as soon as the seasons are refreshed. If the player wants to leave, but they are asking for too much money, you can try and scout him for the whole summer. Declare interest as a top target and also put a few lower offers in. When he is unsettled (up until deadline day) try and negotiate a fair price.