The Portuguese man is set to miss the European Super Cup with Sevilla on August 9 as well as Los Blancos' two opening La Liga fixtures against Real Sociedad and Celta Vigo. The Portugal captain will also be unavailable for selection for A Seleção's World Cup 2018 qualifier against Switzerland.
Ronaldo is expected to be fit again to feature in the third game of the new season, which will be on September 11 against Osasuna.
The 31-year-old, who is currently on holiday in Ibiza with his family, is set to return to Madrid to continue his recovery process in the upcoming weeks.
The three-time Ballon d'Or winner is aiming for a speedy return to the pitch, as he has already attended a medical clinic for specialist oxygen treatment in hopes of accelerating the recovery period from his tragic injury.