Justifying selling a player

Would it ever be possible to justify a sale of a player to avoid the rest of the squad throwing their toys out of the pram?

The example is player A wants to move to a bigger club

Player A is worth 12million

Player A has 18 months left on contract

Continually attempt player A to sign a new contract with no joy

Time to cash in as cannot risk player A leaving for nothing which they will do at the end of contract

Sell for just above market value

Rest of squad starts crying and morale goes down very quickly

It would be great to be able to turn round and give a reason to the squad such as - Player A wanted to move, cannot risk him leaving for free so had to sell but will reinvest in a new player so please do not all get upset.

I would also like to be able to let players know whey they have been made available for transfer such as cannot give you game time, formation has changed etc

I have never let the morale of the squad influence my decisions. If you're that concerned, check the profile page of each player who is unhappy with the transfer and see what their personality type is. If they're professional, hardworking etc then you should be ok. If they're anything other than that then consider picking a squad member who isn't unhappy in their place.