When Real Madrid hosts Ukrainian side Shakhtar Donetsk on Wednesday at Santiago Bernabeu, they will do that without their first-choice goalkeeper, Thibaut Courtois.

The Belgian goalkeeper was absent from the Los Blancos’ 1-1 draw with Osasuna on Sunday, which ended the team’s perfect start to the La Liga season.

However, the Los Blancos revealed the reasons for Courtois’ injury and the extent to which he will be away from the action in a statement posted on the club’s website.

“After the tests carried out on our player Thibaut Courtois by the Real Madrid Medical Services, he has been diagnosed with left sciatica. Pending evolution.” the statement read.

Real Madrid will have to make do with Ukrainian goalkeeper Andriy Lunin who kept in goal for that 1-1 draw with Osasuna on Sunday.

He will also be in goal when Carlo Ancellotti’s side faces Shakhtar Donetsk in the UEFA Champions League on Wednesday.

Meanwhile, Courtois is expected to miss three games, including two UEFA Champions League ties against Shakhtar Donetsk and a La Liga tie against Getafe.

The expected return date is the El Clasico on the 16th of October at the Santiago Bernabeu, which will most likely decide the fate of the La Liga title race.

While Real Madrid and Barcelona share 19 points from 7 games, the Blaugrana is at the top of the table with the goals difference.

Barcelona had beaten Mallorca 1-0 at the weekend and will switch attention to the travel to Italy to face Inter Milan on Tuesday.

Xavi’s men have won one and lost the other of their two UEFA Champions League fixtures this season. They sit in the second position behind Bayern Munich with three points.

Meanwhile, Atletico Madrid will also travel to Belgium to face Club Brugge on Tuesday in the UEFA Champions League.