David de Gea will be under the spotlight when Spain face Iran in their second World Cup Group B match on Wednesday (6pm).
The Manchester United goalkeeper made an error against Portugal to allow Cristiano Ronaldo to score his second goal in a 3-3 draw on Friday.
He was also at fault when he gifted Switzerland a late equaliser in a friendly earlier this month.
Almost 50 per cent of 40,000 fans voting in a poll on Spanish newspaper AS said they wanted Athletic Bilbao goalkeeper Kepa Arrizabalaga to start against Iran.
However, Spain head coach Fernando Hierro has no doubts over De Gea's position.
"David de Gea will be in the starting line-up," said Hierro. "We have full trust in him"
Iran top Group B after beating Morocco 1-0 in their World Cup opener and head coach Carlos Queiroz said his side are in a "win-win situation".
"For us, it's a privilege and an honour to be here."
"It's a unique opportunity for us to play against Spain, one of the candidates to win the World Cup," said the former Manchester United assistant."
"We're in a win-win situation because it's a unique opportunity for our national team to learn more about the game and to grow as players."
Queiroz added: "I have to say, if there was a magic potion to stop Spain that we could buy for a million dollars we would buy it."
"What we can do is keep our determination and our capacity to endure suffering."
"When we defend, which we will have to for many moments, we will fight collectively."
"What we cannot do is to defend and then surrender, that would be dishonest."
"When we have the ball, we must try to win. What happens then is up to the football gods."
Team news
Real Madrid defender Dani Carvajal is available after recovering from a hamstring injury suffered in the Champions League final. He could start in place of Nacho, who scored against Portugal.
Iran have no injury concerns.
Match stats
This will be the first ever encounter between Iran and Spain.
Iran are winless against European opposition at the World Cup, having lost five of their six previous fixtures (D1).
Spain are unbeaten against Asian opponents at the World Cup (W2 D2), though they did lose on penalties after one of those draws (vs South Korea in 2002).
Spain have been eliminated at the group stage in two of the last three World Cup tournaments in which they've failed to win their first match (1998 and 2014) - however, they won the tournament on the other occasion, doing so in 2010 despite losing their first match to Switzerland.
In their 1-0 victory over Morocco, Iran became the first team since 1966 to score a goal without attempting a shot in a half of World Cup football - their winning goal came courtesy of a 90th minute own-goal by Morocco's Aziz Bouhaddouz.
Iran's winning goal against Morocco was scored after 94 minutes and 7 seconds - it was the latest winning goal in a World Cup match since June 2006, a Francesco Totti penalty against Australia for Italy in a 1-0 win (94:24).
D iego Costa has scored eight goals in his last eight international starts for Spain - he scored with both of his shots on target in their 3-3 draw with Portugal.