Mateo Kovacic has been working very hard this preseason to earn a spot in Real Madrid's first team. The Croatian midfielder reported back in training 10 days ahead of schedule to show his commitment and willingness to improve and get some minutes, and Zidane has delivered as Kovacic has been an important player in all three games Los Blancos have played in the preseason stage in North America.
The plan for Mateo Kovacic was to send him on a loan deal to the Italian Serie A so that he could play with consistency and therefore develop into the midfielder he is expected to be. However, Real Madrid might not make any signings for the midfield line and Kovacic could have a spot in the current squad, given that James, Isco and Asensio are not quite as physical as the Croatian, who could replace Modric or Kroos.
Real Madrid will have to make some decisions in the upcoming days, and while it would make sense to send Kovacic on loan, Zidane might ultimately decide to keep him so that he learns from Modric and the other quality midfielders on the squad.