Thats a very simplistic way of looking at it, his value is peaking, theres every need to sell if he wants to be elsewhere.
If he's not buying into the project anymore and wants out we'll sell, and rightly so.
We don't need to sell to reinvest in the squad I think we need to draw a line now, there is noway anyone would agree to him joining Arsenal or Chelsea, we need to put the Manchester clubs and Liverpool in the same bracket otherwise they will think they can get any of our players.Being available for selection wouldn't matter a jot if his heart is set on moving elsewhere, the need to sale stems from the fact that the player will want to leave and down to the fact that we're stilling on £50m which will be diminishing every year which can be re-invested back into the squad.