In that eventuality, and he was a key player, I'd tell him to fcuk off and get his head down as it's only been 3 months since he expressed unswerving loyalty. So, you see, it really is up to the club and the buck stops at the club's door.
What if said player looses his motivation, willingness and performs at a mere 90% and just goes through the motions.
Sulks around the club and dilutes an exceptional team spirt and as result a link in the chail breaks and the team do not perform at the optimum.
This behavious also has a negative effect on the talented youth players coming into the team and llok to senior pros as role models to learn from.
What if it is the players intention subsiquently due to his frustration and anger, to force a move by purposefull exhibiting behaviour to the detrimental effect on the team and the squad.
What if said behaiviour leads the club to sell said unhappy player eventually at a reduced cost, to what was origanally offered due to making a player stay even though his heart (a value the clubs performences are built around) hasnt been in it.
At the end of the day it may legally be the clubs decision but in reality its the dynamices and potenial fall out for the club overall good that comes into decision making.
Im sure this is not what could happen in Lescotts case, but i would say it happens possibility for a lot of clubs (maybe Blackburn Rovers, West Ham and Aston Villa) in why they may agree or more likely be forced into agreeing to sell players.