The former Liverpool keeper said: "The problem is that the goalkeeper is never rotated like the on-field players, because the games are not a physical test for us. I think it is not necessary to change the goalkeeper when he is in form and playing very well like Iker.
"I will continue to train and, if the coach decides to do so, I am ready to play.
"Real Madrid needs a second keeper good and strong. The season is long and chances will come up for me."