According to José Ramón de la Morena on El Transistor on Onda Cero, he is "sure that Real Madrid will sign goalkeeper next season." Meanwhile, the future of Keylor Navas as the Real Madrid keeper is in the air despite some excellent performances recently. The same show is sure that Kiko Casilla will look for a new home given his lack of opportunities.
That does not mean that the Costa Rican will lack competition, however, and according to reports, Thibaut Courtois will return to Madrid to play at the Santiago Bernabeu. Reportedly, the Belgian has informed Chelsea that he wants to sign for Real Madrid and he does not want to renew with the Premier League side. That means he would potentially leave for free next summer and Chelsea will try to avoid that from happening.
If Chelsea do decide to allow Courtois' contract to expire, Navas would be the number one for another year. If Casilla leaves though, it would mean Real Madrid have to sign a back-up keeper. According to De La Morena, "Courtois has told Chelsea that he is willing to continue for another year before leaving on a free next year."