Carvajal, who recently signed a new long-term contract with Los Blancos, has already made 10 appearances in all competitions during the 2017-18 campaign.
However, the Spain international is now facing a spell out of action after Real Madrid confirmed the condition on Saturday night.
"Following tests carried out on Dani Carvajal, he has been diagnosed with a viral pericardium infection. His recovery will continue to be assessed," read a club statement..
The 25-year-old, who will also miss Spain's upcoming 2018 World Cup qualifiers against Albania and Israel respectively, could reportedly miss the next two months of the season.