Recently we saw news about João Félix joining Barcelona because of interest in this team but this transfer is not going to be done because of the financial issues in Barcelona.
Even if Barcelona hires João Félix and he plays there for a loan, still, Barcelona needs to release two players to hire João Félix which is expensive for this team.
Joao Felix's future is somewhat uncertain at the moment, it is pretty obvious that he isn't going to play for Athletico Madrid again, so he has to leave if he wants to continue playing football. I don't think Barcelona can afford to get him before this transfer window closes, Barcelona are in a financial crisis, thus there is no way they can get Joao Felix registered with them, except there are outgoings. Having said that, i think Joao Felix is going to end up in Saudi Arabia, their transfer window doesn't close at the same time with that of Europe, so they still have some time to work on the deal if Joao Felix's move to Barca falls through.