In a long message posted on Instagram, Ramos has said that he will not be able to help his team in the “highly demanding matches” against Liverpool.
Defending Spanish champions Madrid will take on defending Premier League champions Liverpool in the quarter-finals of the Champions League this month.
The first leg of the tie will be held in Madrid next week, with the second leg to be played at Anfield the following week.
Ramos has picked up a calf injury while on international duty with Spain, and the 35-year-old Spain international central defender has said that he will not be able to play against Liverpool.
Madrid are third in the La Liga table at the moment with 60 points from 28 matches, six points behind leaders Atletico Madrid.
Meanwhile, Liverpool currently find themselves seventh in the Premier League table with 46 points from 29 matches, five points behind fourth-placed and London rivals Chelsea.