Spain keeper Iker Casillas says he was responsible for the reigning world champions' disastrous start to the defence of their crown.
Vicente Del Bosque's side took the lead against the Netherlands before suffering a humiliating 5-1 defeat.
Long-serving Casillas was at fault for at least one goal on his 155th appearance for Spain.
"I wasn't at the level I needed to be. I have to accept all criticism," admitted the Real Madrid player.
Spain, looking to win a fourth consecutive major international trophy, were humbled and humiliated in the repeat of the 2010 World Cup final.
They took the lead through Xabi Alonso's penalty before the Netherlands hit back as Robin van Persie and Arjen Robben both scored twice, while Stefan de Vrij also netted.
"I didn't do things like I should have, especially to start a World Cup," added Casillas, who was dispossessed by Van Persie for the fourth goal.
"It wasn't one of my best games."
De Bosque, who masterminded Spain's 2010 World Cup triumph, said he felt "sick" by the result.
But the 63-year-old refused to publicly blame any of his players.
"When a team loses a match it's not just the performance of one single player, its a weakness in the total squad," Del Bosque said.
"We can't blame anyone, least of all Iker Casillas."
Speaking about the result, he added: "I feel sick, ill at ease, but with the courage a defeat must not sink us.
"It is not a happy moment, but first of all I want to congratulate the Dutch team, who were superior to us.
"We have been overwhelmed.
"We are a team of good professionals and good lads - everyone hurts. There will be time to talk."
Spain's next game is against Chile, who beat Australia 3-1 in their opening game, on 18 June.