Both teams have only pride to play for, having both been eliminated from Group A, with Russian Federation and Uruguay already guaranteed last-16 berths.
Portugal, the defending European champions, are tied with Spain at the top of Group B with four points each.
"We can't afford to relax".
Caceres consulted with VAR to award Portugal a penalty for Morteza Pouraliganji's foul on Ronaldo, Europe's highest global goalscorer, amid vociferous protests from the Iranians and their numerous supporters at the Mordovia Arena.
Isco, who scored the 2010 world champions' first goal on Monday when he took Andres Iniesta's pass and crashed it into the roof of the net, echoed his coach's relief.
Spain must cut down on careless errors if they are to advance to the latter stages of the World Cup in Russian Federation, midfielder Isco said after the Roja booked a place in the round of 16 on Monday.
"The temperature in my body, it comes from 46 (Celsius) to 250, so you understand why I need to take the jacket off", he said.
Queiroz admitted it would be "a special day" facing his homeland but said friendships would be put to one side as he bids to make history with Iran.
The victor of Russian Federation and Uruguay's Monday night match takes the group.
"We don't choose our opponent in the last 16".
Carlos Queiroz's men relied mostly on counter attacks and while forward Sardar Azmoun showed plenty of glimpses of his talent, it was not enough to trouble the Portuguese. Since Denmark and Australia drew, they too could be split by fair play. "We know both teams, the football gods will decide".
Senegal plays Colombia, and Japan plays Poland, at 10:00 a.m.
"The people deserve to know what are the rules of the game because this is a game of the people", Queiroz said, adding that if he is indeed punished for speaking out, "I'll be here to try to swim and survive". The player was deeply affected by this matter. They way they set themselves up makes them very hard to play against which means that it may take something special from Ronaldo to break the deadlock.
Portugal go into the contest as heavy favourites to progress, but veteran centre-back Pepe strongly insisted the job was not yet complete. A draw with already-eliminated Costa Rica would be enough for Switzerland and defeat could still see them qualify if Serbia also lose.
England striker Kane surged ahead of Ronaldo and Romelu Lukaku in the race for the World Cup Golden Boot after hitting a hat-trick in a 6-1 demolition of Panama yesterday. The Danes would top the group with victory.