I mean, he can just refuse to play? It'd actually be more dignified than play, try to play well, possibly help the club that you feel 'objectified' by, while also helping blur the bad image of seniors if your good performances will mask the obvious selection issues they cause? IMO write off the losses, middle finger everyone and start your life in Turin. He wouldn't help anything if he played good football for altruistic-purist reasons at this point and if they call him 'unprofessional' because he didn't respect the contract, all the more reason to see the board/management in bad light.
Will be interesting to see if Sarri can actually work with him. Different league and less focus on the personal responsibility without having to live up to the 'next Xavi' tag could be what he needs.