After Vinicius Junior got injured there is not some empty slot in the squad for other players and Ancelotti should make some chances for the next games that's why the biggest winner of this situation is obviously Brahim Díaz because he can get back to the position he likes to play and he can be the left winger in the new systems after the changes by Ancelotti when he uses the classic 4-3-3 plan.
Vinicius Jr. is a great asset of Real Madrid and he will be one of biggest star players in La Liga too. He must be protected more by referees in the league. They must use yellow cards or red cards if fouls of defenders against Vinicius is dangerous enough. Many young players got serious injuries that destroy their career. Brahim is like Asensio who struggles to get a good position in Real Madrid. It he won't claim a good position soon, he will be like Asensio, only a substitution for Real Madrid. Hopefully he will take this chance, from the unlucky injury of Vinicius, to make big change for his own career.
Brahim is still young, he can also become an asset for Madrid if he can improve his performance and convince the coach. if strong to compete then will survive. but if not then it's best to leave to play at another club that does allow for better playing time.