The 2020-21 season was the second with the most minutes played by Luka Modric since he landed at Real Madrid in the summer of 2012. Only in the 2013-14 season, when he was 28 years old, did he play more than now, at 35. Then he played 4,061 minutes for the 3,721 minutes this year, although it must be taken into account that that year Real Madrid won the Copa del Rey (it was also played in a double game) and the Champions League.
Now, with the newly renewed Croatian until 2022, a dilemma presents itself for Ancelotti's Real Madrid, because Modric will play the Eurocup with Croatia after a grueling season with his club in which he has arrived with the reserve driver turned on to the most important matches. Next year, at 36 years old, Ancelotti is obliged to dose him. You cannot repeat another course like the current one.
The problem that the Madrid team has right now is that in the current squad they don't have a natural replacement for Modric, because Fede Valverde plays in the same position but is a different profile. And, with Mbappé as the highest priority and the crisis caused by the coronavirus, It also does not have the financial muscle to make a large outlay in the market beyond the return of Odegaard and Ceballos.
Besoccer
The profile of the Croatian is given by Dani Ceballos. In fact, in 2017 he was signed with the poster of Modric's heir, due to their similarities in the game. The Utrera was important in Madrid in the only season in which Zidane was not (2018-19), but with the French coach he has never had regularity. After two good years at Arsenal, his priority is to succeed at Madrid and it remains to be seen if Ancelotti gives him confidence.
There's also the Odegaard option. I am trying Zizou last summer, when he asked for his return. However, the Norwegian is much more comfortable ahead, in the midfielder, without so much responsibility in the exit of the ball. Probably over the years he will gradually delay his position, as happened to Modric in his day, but right now he is a different profile.
Antonio Blanco, from Castilla, more will come to be the replacement of Casemiro than that of Modric, although it also serves to give oxygen to the Croatian by changing the system.