The world and European Champions face their Iberian neighbours in the first last-four fixture on Wednesday, and Iniesta believes that the Portuguese will adopt a similar defensive style of play to the one they used in the last 16 of the 2010 World Cup, when the Spaniards defeated their neighbours 1-0.
|Semi-final profile: Portugal
Speaking at a pre-match press conference, the 28-year-old said: "Portugal’s style or idea is more or less the same as it was in the World Cup. We will see how they set up but I think they will [sit back and] wait for us, they will try to close the space inside so that we have less fluidity to our play.
"They have a very strong and hard-working central midfield – they have players who are at a very high level. If we don’t play well, Portugal will control the game and that is exactly what we don’t want."
The Seleccao did exact some revenge on the Spaniards for their World Cup exit back in November 2010, as Paulo Bento's men hammered Vicente del Bosque's side 4-0 in a friendly in Lisbon.
However, Iniesta does not believe that result will have any bearing on how Wednesday's encounter will play out, although he warned that La Roja must learn from their mistakes that day.
He added: "Fortunately that was some time ago; it was a different game and it has nothing to do with the game we will play tomorrow. All of the things are important to analyse, though. We have been warned of what can happen if Spain play without intensity, without concentration.
"They are one of the best teams, they have players who can decide games and it’s a very demanding fixture. We have to be fully focused for 90 minutes and concede virtually nothing if we want to win the game.”