Madrid's medical report on Thursday did not state how long Llorente would be missing for, although reports in the Spanish media said he would be out for almost a month.
That means the Spaniard would miss Saturday's La Liga derby against Atletico Madrid and the Champions League last 16 first leg at Ajax Amsterdam.
Llorente had only recently returned from a hamstring injury which had kept him sidelined for three weeks and he was chosen ahead of Brazil midfielder Casemiro in the Copa del Rey semi-final first leg at the Nou Camp.
The 24-year-old faces a battle to be fit for the return leg of the cup 'Clasico' on Feb. 27 and the La Liga fixture at home to Barca on March 2, and is almost certain to miss league games against Levante and Girona before then.
(Reporting by Richard Martin; Editing by Christian Radnedge)
