Higuain could be out for two months if a specialist confirms he needs to undergo surgery on his back problem.
Higuain, Madrid's top scorer for the past two seasons who missed Monday's 5-0 defeat to Barcelona with the injury, has been diagnosed with a herniated disc.
Madrid have agreed that the Argentina international, who has scored seven times in La Liga this season, needs an operation but have decided to consult a specialist for a second opinion before sending the 22-year-old forward under the knife.
Dr Carlos Diez, Real Madrid's medical chief, said in a statement on his club's website: "The player met with a specialist, the coach, the fitness trainer and the entire medical staff. After a period of five to six weeks, during which no improvement was seen, we all agree that he should have surgery.
"Now we must now decide what specialist to see for a second opinion, and if we are all in agreement, proceed with the operation. Should this be the case, Higuain will be unable to participate in sport for approximately two months."