The La Liga champions fell further behind Barcelona after a 2-2 draw with Celta Vigo to pile pressure on the Frenchman before the midway in the campaign.
Visiting coaches traditionally give their post-match press conferences first so they can begin the long journey home but Juan Carlos Unzue was kept waiting for Zidane to finish dealing with his faltering Madrid team and eventually had to go first.
When Zidane finally emerged ashen faced he was asked by Spanish television what had been said.
He replied: ‘That stays between us but obviously we are all angry. But that is normal. With the good first half that we played, it’s only right that we are not content with the second half or the result.’
‘The opposition pressed better in the second half and we could not circulate the ball. We lost possession too much.”
Madrid had come back from going 1-0 down thanks to two Gareth Bale goals in 95 seconds but they were poor in the second period and only a penalty save from Keylor Navas stopped them falling to defeat.
Although they have a game in hand to play, Real Madrid are virtually out of the title race with matters made worse by Barcelona’s recent acquisition of Philippe Coutinho.
Asked about the huge gap between Madrid and the other sides at the top Zidane said: ‘We can’t talk about the league [table] we have to just concentrate on one game at a time and trying to win matches.’