The Portuguese has been ruled out of the clash at the Mestalla with a hamstring injury, but Iniesta has warned his side that Los Blancos still possess a number of attacking positions.
"Cristiano is very important for them as he scores a lot of their goals but I don't think Real Madrid will change their game as a result of Ronaldo's absence," Iniesta told Sport.
"We're confident and know where we can do the damage. If we're playing at our top level, we will have many chances to win the game."
Barcelona have lost their last two games.