Bale was a notable omission in the Real squad that face off against the Premier League giants at the Etihad this evening as suspended captain Sergio Ramos was included.
With Los Blancos aiming to overturn a 2-1 deficit from their first-leg clash for a place in the quarter-final of Europe's elite club competition, his absence, despite the recent issues at the club, raised plenty of eyebrows.
"I will explain because many things are said," Zidane said. "We have a relationship of respect between player and coach, that is clear. The only thing I can say is that he has decided not to play, and the rest is between him and me."
Despite Bale's agent Jonathan Barnett reiterating over the past few weeks that he will remain at the club, the latest decision appears to signal the end of his time at the 13-time European champions.
But Zidane remained mum on the latest drama as he grew agitated by questions posed around the club's highest-paid player in the pre-match press conference.
"I have already answered before about the situation. The rest is a conversation between the player and the coach, and I am not going to tell you anything," he added.
"Gareth Bale is a Real Madrid player, nothing changes. I respect that. He has decided not to play. All of us here are focused on tomorrow's game."
