Carvajal scored in the 2-0 win, which failed to attract a full house for the opening game of the LaLiga season.
The defender said, "This support is unique, but we are in August, I'm from Madrid and I can tell you, I'm sure the stadium will be filled like every Sunday in September.
"I have not noticed it much, we've felt the heat of the game.
"We work for those 48,000 that come, for those who see us at home ... The stadium will be full."