Madrid take on City in the second leg of their Round of 16 tie on Friday and are trailing 2-1 from the first leg, with the Welshman left out of the 24-man squad entirely.
The Welshman has been a peripheral figure at Los Blancos this season and had been an unused substitute for five successive games before being left out of the matchday squad entirely in the final game against Leganes earlier this month.
Indeed, Bale has been in the headlines for his actions as a substitute recently – appearing to be sleeping during the win over Alaves while mimicking to be using binoculars from the stands in the recent triumph over Granada.
“In the end many things are said and we have a respectful relationship between the coach and the player,” Zidane told his pre-match press conference, via Marca.
“It is a private conversation, but I can only tell you that he preferred not to play and the rest is between him and me.”
Zidane was then asked if not including Bale was a personal decision, to which he responded: “Yes, but I’m not going to tell you anything else because it’s something between him and me.”
Has Bale disappointed Zidane? “He has not disappointed me and I will not tell you anything. It is the third question about Gareth. I respect him and everyone and these things have to stay in the locker room.”
Does Bale have a future at Madrid with Zidane as coach? “I don’t know, he’s now a Madrid player, nothing changes and I respect that. He preferred not to play and that’s the only thing I can tell you. We are concentrating on tomorrow’s game.”
Bale has played just 1,261 minutes this campaign – the lowest of his stint in the Spanish capital – and has missed 13 games through injury while he was overlooked by boss Zinedine Zidane on a further 16 occasions.
James Rodriguez and Mariano Diaz – two other out-of-favour attacking players who look set to leave Madrid this summer – have also both failed to make the cut for the squad.