For Brahim Diaz: If Real Madrid is willing to renew your contract, you dare not say no. Unless you consider yourself as a huge talent who doesn't want to be in anyone's shadow again. But people who left in such a manner doesn't always end better than when they were in Madrid.
For Nunez:
If it is possible, he should just go to Napoli. I just have this strong feeling that Darwin Nunez hasn't given his best yet in football.
Brahim Diaz is a good versatile player for Real Madrid. Carlo Ancelotti have always count him to become one of the very good player for the club and also a player to relied on when things gets out of hand. Who doesn't feel the pressure from this particular player when he's on the pitch? Everyone literally feels his presence because he's regarded to be a player that's always forcing attacks and also making tackles good enough.
However Xabi Alonso would want to see each of this players prove themselves to him because he's new to Real Madrid system and trying possibly hard enough to cope. Creating good chemistry between the players would be his first objective before moving unto the next.