Real Madrid goalkeeper Thibaut Courtois will be sidelined for a further four to six weeks, sources have told ESPN, after the club confirmed he suffered a meniscus tear in his right knee during a training session on Tuesday.

The 31-year-old Belgium international had been expected to return to Madrid's squad after he ruptured the ACL in his left knee in August.

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However, he underwent an MRI scan later on Tuesday that confirmed the damage to his right knee suffered in the training session.

"Following tests carried out today, our player Thibaut Courtois has been diagnosed with a ruptured internal meniscus in his right knee," the club said in a statement.

Sources told ESPN that Courtois left Tuesday's training session in tears and very upset.

Courtois was due to make his comeback at the end of April and Ancelotti himself acknowledged after the Osasuna game that both the 31-year-old and defender Éder Militão would be available for the Champions League quarter-final against Manchester City.

However, after the latest setback, neither Madrid nor Courtois want to take any risks in the evolution of the new injury, so it is likely that the goalkeeper will not play for the rest of the season.

Information from Reuters contributed to this report.