The Frenchman affirmed that Rodriguez will stay at the Spanish club, but he has to make a big effort and fight for his place.
The 25-year-old struggled last season at the club and has been linked with an exit, but Zidane has given him another chance.
The Colombian joined the club two years ago from Monaco.
"There are many players in that position, so nothing is closed. We will talk about this when we return to Madrid".
The Frenchman admitted, that some players have to leave, he didn't reveal yet who could be the ones to quit. Isco has been most of the time out of the first-team last season and his future at the club is uncertain.
He said: "There are many players in this position and it is difficult to fit them all in. Moreover, they are all very good. We will make decisions.
"I do not want James to leave. He is a Madrid player, he just wants to play more, but you have to do what he is doing and work.
"I hope to play him more this year but I want everyone to give their maximum, and then I decide before every game.
"And I have 25 players, so I do not have anything against James, people always ask me the same. James is well in Madrid".