Tevez's agent (Raiola, I believe) agitated for a move away from Utd, he came to us and then agitated for a move away from us (almost torpedoing our title bid in 2011-12).
Yaya's agent (the Russian/Ukrainian chap) agitated for a move away from Barça, he came to us and then agitated for a move away from us.
Neymar agitated for a move away from Santos, then from Barça, and there are constantly rumours of him wanting out of PSG (the latest used as the rumour of why De Jong chose Barça over PSG).
Rabiot's mum agitated for a move away from us when he was a kid, now she is agitating for a move away from PSG in similar circumstances.
It'll happen to whatever club he ends up at next because these types of players always repeat.
It's the reason that our current management team put so much effort into researching the personality and soft skills of players as well as footballing ability.
One person like this can fuck the group dynamic, completely.