Correct me if I'm wrong but couldn't any buying club essentially tell him to write off his £17m and they'd pay it to him as a sign on bonus or pay it over the lifetime of his contract? Nothing wrong with that surely?
I think that might be what Barca are trying to pressure us into doing, and really, pushing another club into doing that is the only option they have apart from paying it themselves. Is there anything anywhere about that £17m being net or gross because if it's the former, that is an insane bill to willingly take off Barca's hands as we'd end up paying the tax on top. You could fund a smaller PL club's whole transfer window on that payment alone.
There's also a whole legal minefield here for Barca in potentially setting contractual precedent with whatever they do with FDJ. If they openly acknowledge he
should get that money, either by paying it themselves or formally signing something that says they mutually agree with the player to waive future payments (because United or whoever else is picking up the bill), what happens when Depay, or Ter Stegen, or Umtiti or whoever else in future needs to be sold or wants out and the buying club doesn't want to pick up Barca's IOUs? They have tied themselves in knots with this stuff and could be in a really bad place.