Real Madrid defender Sergio Ramos will be out of action for five weeks, coach Carlo Ancelotti confirmed on Friday.
Spain international Ramos, 28, suffered a torn hamstring in Wednesday's 2-1 La Liga win over Sevilla and limped off after just nine minutes, replaced by Nacho.
"Sergio's injury is a serious one. He'll be out for five weeks," Ancelotti said.
Ramos, who had already been ruled out of Saturday's derby against Atletico, could also miss both legs of Champions League round of 16 against Schalke, on February 18 and March 10.
The centre-back's absence is a major blow for Real, who already had to do without James Rodriguez (foot), Pepe (rib) or Luka Modric (thigh).
Against their Madrid rivals, Real are set to start with Raphael Varane, 21, and Nacho, 23, at the heart of the defence.
"I trust those two players. They are very good players. They are dedicated and willing to play. I am convinced they will do good things on Saturday", Ancelotti said.
Real, currently top of the league with 54 points, face Atletico on Saturday for the 10th time in the past year in all competitions.
Source: AFP