And Real have agreed to trigger that clause in January.
However, Don Balon says a number of Real players do not want the 23-year-old and have advised Courtois be brought in instead.
The Belgium international is desperate to return to the Spanish capital after three successful years on loan with Atletico Madrid.
And it is a feeling echoed by a number of players in the Real dressing room, including club captain Sergio Ramos.
The centre-half has reportedly championed the arrival of the 25-year-old due to his vast experience - something that Kepa cannot offer.