Vicente del Bosque's tactics were questioned by his predecessor as coach, Luis Aragones, after last week's 1-0 defeat by Switzerland, who suggested the European champions had not been ambitious enough from the start.
Del Bosque deployed David Villa as a lone striker in that game and although Spain dominated possession they found it hard to penetrate their opponent's well-marshalled defence.
He brought Fernando Torres back into the starting lineup in a two-pronged attack with Villa in Monday's 2-0 defeat of Honduras and is likely to repeat the tactic against the Chileans in Pretoria on Friday.
"Everyone has the right to express an opinion and give their view on how the team is playing," Iniesta told a news conference at Spain's training base on Wednesday.
"But we can't get dragged into a situation where we have doubts or into an argument over what one or the other person is saying," added the midfielder, who looks to be winning his race to be fit.
"We are clear about what we have to do and are confident about our chances and anything beyond that is unimportant."
As it stands, Chile top the group on six points from two matches, Spain and Switzerland both have three points in second and third respectively and Honduras have none.
A win for Spain, one of the pre-tournament favourites, would put them through to the last 16, where they will almost certainly face either five-times champions Brazil or Portugal, depending on the final standings in Group G.
Ivory Coast still have a chance of qualifying but would need to thrash North Korea and hope the Portuguese lose to Brazil.
KEY SUSPENSIONS
Chile, who need only a draw to go through, have two key players suspended -- holding midfielder Carlos Carmona, who played well in their first two games, and playmaker Matias Fernandez.
Rodrigo Millar is likely to come back in for Carmona and Jorge Valdivia is expected to replace Fernandez, playing just behind Humberto Suazo.
The shaven-headed striker is still shaking off a hamstring injury but played 45 minutes against Switzerland.
Central defender Waldo Ponce told a news conference on Wednesday the team were unlikely to sit back, raising the prospect of an open game with plenty of chances for both sides.
"We've never changed our playing style," Ponce said.
"We play the same way in our friendlies, in the matches against the reserves here in training and that's the best way to take on a great team," he added.
"Our coach would never tell us to go out and protect a draw or play for a draw, because it never works out like that."
