They can damage him as a footballer of course but that just reduces the sale value of the asset. Presumably there is an accountant somewhere who gives no feks about the muppetry, who is just saying path x is cheaper than path y and once the facing off and being nasty has been done we, Barca, still have to take path x. Path x is most likely paying FdJ amount z, which is the smallest amount he is owed that he is willing to accept, in order to leave.
The only real question is getting agreement on amount z. Anyone can see that the cards are with FdJ as failure to agree amount z causes more harm to Barca than it does to him. That's where we still are and where we will likely stay till the end of the transfer window. Everything else appears to be noise.