The centre-back was forced off the pitch after Lucas Hernandez accidentally caught him in the face, and several medical examinations carried out on Sunday morning finally determined the problem.
A fractured nasal bone, which is at the top of the nose, and will surely keep him out of Tuesday's Champions League clash against APOEL Nicosia.
He spell on the sidelines is still of undetermined length but reports have anticipated a two-week rest and, when he eventually returns, he will do so with a protective mask.
Parte médico de Sergio Ramos.
— Real Madrid C.F. (@realmadrid) 19 November 2017
https://t.co/gwTmnWzsGS#RealMadrid pic.twitter.com/T1W5jVrHPY