We don't sell Ansu if he scores a bunch of goals. We sell Raphinha as he will be declining soon within 2 yrs.
Not rocket science. You sell the high value (Raphinha) and keep the player who will never sell above what you already lost (Fati) and hope Ansu can actually turn out elite. He is a real LW/SS the same way they shoehorn Raphinha, use Ferran, and Rashford. He can be an answer.
If he sucks and scores like 10 goals all year then ok dump him and be done with it.