The Welsh forward was left out of the squad that lost 1-0 to Premier League club Tottenham Hotspurs in the Audi Cup on Tuesday as Zidane told reporters the nimble-winger was unfit to feature for the Los Blancos.
“He didn't travel because he wasn't fit.
"After speaking with the doctors, the best thing was for him to stay in Madrid. He stayed back and is training there. It was a joint decision between the player, medical staff and the coach."
But Bale, who was said to be unfit was spotted playing golf while Real were losing to Tottenham and Zidane has insisted he is not ready to make any judgement about the player’s situation.
"I am here, I'm here with my players, so I can't really say much. I hope that he has trained there.
"I'm not going to stop anyone from doing something, you know? Everyone has their own responsibilities and we will see what he's been up to in Madrid.
"I'm not getting involved with his personal life. He stayed back to train. I think he has trained. And we will see about everything else."
Having stressed his sentiments on Bale’s golf row, Zidane believes his side will have a good season despite conceding more goals in their pre-season games after defeating Fenerbahce 5-3 on Wednesday.
"Yes, we're going to resolve that, we're going to work hard and I am one with my players," he added.
"I know we are going to push on and we're going to have a really good season. And that's it.
"Nobody likes to concede three goals. But the important thing for us is the victory. We won with five goals, and we could have scored more, but that's it."