Spanish defender Dani Carvajal has been ruled out of action with a heart problem, with Marca reporting that he could be out of action for up to six weeks.
Carvajal will not be in the Madrid squad to take on Espanyol at the Bernabeu on Sunday, with a club statement saying he "has been diagnosed with a viral pericardium infection."
The statement said the right-back's "recovery will continue to be assessed."
He has previously played every minute for Zinedine Zidane's side in La Liga this season, and the setback means he drops out of the Spain squad for the World Cup qualifiers against Albania and Israel.
Earlier this month, Carvajal signed a two-year contract extension and said he would be "delighted" to be Real Madrid captain in the future.
The 25-year-old said: "I'm very grateful to the club. I've been fortunate to win every title with Real Madrid, and I'm looking forward to winning them again.
"I would like that. The day that I leave, everyone knows that I have given everything for this club and that they are proud."
The right back - a crucial cog in the wheel for Los Blancos has the most assists (6) for a defender in the UEFA Champions League since the start of last season, a historic one where Real Madrid successfully their European crown.
With left back Marcelo also out of action with an injury, this is likely to pave the way for the 18-year old Moroccan Achraf Hakimi and Nacho to get an extended run in the first team.