Toni Kroos has suffered another injury in the loss against Real Sociedad and the German could face two weeks on the sidelines.
The injury is a grade II tear of the abductor and he will join Mariano Diaz, Marco Asensio, Gareth Bale and Marcos Llorente in the physio room.
He will miss both legs of the Copa del Rey clash with Leganes, along with the LaLiga Santander games against Real Betis and Sevilla.
It seems unlikely that he will make the first leg of a potential Copa del Rey quarter-final, should Madrid qualify, and he is a doubt to face Espanyol in late January.
It remains to be seen who Santiago Solari will turn to, with Dani Ceballos, Fede Valverde and Isco being the obvious candidates.
In a month with heavy fixture congestion, the coach cannot expect Llorente back for at least another two weeks either.