The Sun reported Zidane had a meeting with Perez last Wednesday—he quit the club the next day—and fell out with the figurehead because he wanted to recruit both Hazard and De Gea this summer (h/t Alexander Netherton of Eurosport).
According to the article, Zidane was keen on Chelsea winger Hazard as he sought to boost his attacking options following this term's miserable La Liga title defence, but Perez refused to green-light the move.
One can understand where Zidane—himself a supreme dribbler of his era—might have become infatuated with Hazard, who has also shown a particular strength for running with the ball at this feet, per WhoScored.com:
As for De Gea, it's understood Zidane saw the Manchester United stopper as his ideal upgrade between the posts, but Perez was content to keep faith in Keylor Navas.
De Gea strikes as the more difficult deal of the two to pull off, considering the Spain No. 1 has always appeared happy at United.
Samuel Luckhurst of the Manchester Evening News reiterated manager Jose Mourinho's desire to keep hold of De Gea:
The goalkeeper is an alumnus of Atletico Madrid and hinted in March he's perhaps not interested in a return to his native country anytime soon, saying he doesn't feel the same affection or respect he does in England, per TalkSport.
Hazard, on the other hand, suggested in May he will wait to see who Chelsea sign this summer before making any decision on his future, per the Telegraph's Matt Law, which was hardly encouraging for his employers to hear.
Goal recently looked at what the 27-year-old could bring to the Estadio Santiago Bernabeu, with veteran Cristiano Ronaldo now 33 and Gareth Bale's place in Madrid a hot topic of discussion:
Zidane's exit from the Real helm was a shock, considering he had just become the first manager to lead a team to three successive UEFA Champions League wins.
Some will argue the aim should be to build on that achievement, while others would argue a working formula shouldn't be tinkered with.
Marca's Euan McTear hinted Navas, who joined the club in 2014, could remain an adequate 'keeper for Los Blancos:
Regardless of the Costa Rican's credentials, Perez's refusal to budge on deals for Hazard or De Gea seemingly proved too much for Zidane, who may now prioritise creative control over transfers at his next club.