Zidane defended his player during Wednesday's press conference, insisting that the hip injury was sustained during the match against Barcelona.
"He let me know about it after the Clasico," Zidane told reporters. "There was talk later about how he might have had something before, but I trust my player.
"It was after the match, not before.
"He then went on holiday like all others, but still wasn't good when he returned.
"A week passed between the match and the tests.
"I do not think he got injured during his holiday, as he was injured when he departed on his holiday.
"It was after the match that he was affected, although he didn't know exactly what was wrong.
"We didn't give it much importance at the time, but then realised that it was more important.
"It's not nice to see a player get injured."
Staying on the subject of strikers, the Frenchman was then asked if Real Madrid planned to add another forward in this window.
"I will ask for health to all for King's Day, but nothing about goalkeepers or strikers," the coach said.
"It's true that the president came along and that we talked about all sorts of things.
"There won't be a signing this very day, but anything could happen later.
"Someone might come, but they also might not.
"What I don't want is for anyone to depart.
"A coach builds his squad at the start of the season and I'll fight with them until the end."