Stefan Savic, the Montenegro defender, knows how bad his injury is now.
The Atletico Madrid man suffered an injury against Levante in the 1-0 win on Sunday and had to go off after eight minutes, replaced by Jose Gimenez.
"Savic took tests on Monday to study the extent of his injury against Levante. They confirimed that our player has suffered a grade two hamstring tear."
The player is set to be out until February, missing matches against Huesca, Getae and Real Betis as well as the Copa del Rey quarter finals.
Another problem for Diego Simeone who has Diego Costa and Felipe Luis missing.