Ancelotti is definitely thinking about the best tactics and might return to the 4-3-3 formation. In this setup, Vinicius would play on the left, Mbappe in the center, and Rodrygo on the right wing. This could be Madrid's lineup for next season. However, can Madrid really afford to replace Toni Kroos, who has been central to their playing style? A new transition in tactics under Ancelotti's supervision could be great, but Kroos will be missed. Still, I believe Madrid has quality backups for every position on the field.
In Real Madrid’s midfield, they have a lot of backups and if you watch closely at what happened, they don’t want all of their midfields to leave the club at once. Some years back, it was Casemiro, Kroos and Modric. After Casemiro left to Manchester United, they still didn’t feel his absence and were able to cover up with a good replacement. I believe Kroos and Modric all wanted to leave the club last season but they persuaded Modric to stay back for one more season. I am sure that during his stay now, he will only be teaching the young ones that will replace them how to handle the midfield when he finally leaves. They have the backups but they have to do some smart transitions in other to continue remaining the great team they are as usual in La Liga and the champions league.