An ankle tendon injury sustained against Sporting CP on Tuesday will keep Gareth Bale out of El Clasico, with the former Tottenham Hotspur man also potentially needing reparative surgery on the damage.
In what is a huge blow for Real Madrid, the club confirmed on Wednesday that the Welshman has suffered a dislocation of the peroneal tendon in his right ankle.
Substituted in the 58th minute for Marco Asensio, Bale was seen hobbling off the pitch in some discomfort.
After the match, Zinedine Zidane was cautiously optimistic that the 27-year-old would not be out of action for any sustained period of time.
"He suffered more of a twist than a knock, but we will have to wait and see what the problem is," the Frenchman told reporters.
But medical tests conducted following Real's 2-1 win over Sporting show that the injury is worse than first thought, with Bale also possibly requiring surgery to repair the damage.
"After tests carried out on our player Gareth Bale at the Sanitas La Moraleja University Hospital, he has been diagnosed with a traumatic dislocation of the peroneal tendons of his right ankle. His recovery will continue to be assessed," read a statement on the club's website.
Definitely out of the December 3 El Clasico, the attacker is also in danger of missing the Group F decider against Borussia Dortmund and the start of the Club World Cup later in the same month.
No official recovery timeframe has as yet been given by Real Madrid officials.
