The 27-year-old recently moved to the Spanish capital from Levante to provide competition for Casillas, but he is hoping to learn more from the experience of challenging the Spaniard for a spot in the team.
"I have always faced everybody in a responsible way and I will do what I have always done," Navas told reporters. "I will try to learn from Iker, and I have to give 100%.
"I can talk about what I have experienced so far and for me it has been worth it being at Madrid, and nobody knows what will happen in the future."
Navas was on the bench as Casillas started the first leg of the Spanish Super Cup against Atletico Madrid on Tuesday night.