Iran coach Carlos Queiroz said Tuesday his team's Group F match against Bosnia-Herzegovina at the World Cup on will be like a tournament final.
Iran play already-eliminated Bosnia in Salvador on Wednesday with a chance of reaching the second round for the first time.
"Tomorrow is our World Cup final," Queiroz said. "As simple as that."
Iran must win to have a chance of going through, while Nigeria only need a point against already-qualified Argentina in a game being played at the same time in Porto Alegre.
"We have to do our job, play our game and win the match," Queiroz said. "The rest is in the hands of God."
Iran have faced criticism for their dour defensive tactics after a 0-0 draw against Nigeria in their group opener. The Iranians also spent much of their game against Argentina on Saturday packing the defense, but created several chances on counterattacks and nearly caused a major upset before conceding a late winner by Lionel Messi.
Queiroz said there will be no major change in tactics.
"I don't think we should change too much," he said. "We just have to be ourselves and play our game and try our best."
He said there are huge expectations in Iran from the fans.
"The day we left Tehran, we knew, everybody knew, that we didn't come here to win the trophy," said Queiroz. "But with the prospect of reaching the top 16, we raised the expectations."
"For 80 million Iranians, it is great and fantastic pride to go to the next round," he said.
Iran lost to Argentina with a spectacular last-minute goal from Messi. Queiroz said that would not have happened if his players were more experienced.
"In Europe, we would not see any play in the last five minutes of the match," Queiroz said. "Players would drag the game, roll on the pitch, but my players are not so cunning."
He reiterated his criticism of the referee of the game against Argentina for failing to award what he claimed was a "clear" penalty for Iran and called for the introduction of replay technology at the matches.
"The game has become so fast and dynamic that for the referees it is impossible to take 100 percent correct decisions," he said.