The Costa Rica coach, Jorge Luis Pinto, has called on Fifa and the match officials to watch Holland’s Arjen Robben closely in their quarter-final, claiming he was “really worried” after the forward admitted diving to try and win a free-kick in his last game, against Mexico.

Robben has consistently been Holland’s most potent weapon during this World Cup but after he won a last-minute penalty against Mexico, which Klaas-Jan Huntelaar converted to win the match, there was a furore over his alleged diving.

While he insisted that he was fouled for the crucial penalty, after the game Robben admitted diving to try to win a free-kick in the first half. Pinto said he was “really worried” that Robben would try to con the officials.

“This is something that makes us worry a lot. We’re really worried about that. I would like to ask Fifa and the referees to watch Robben closely.

“I think he is one of the three or four best players in the world,” said Pinto. “He is a great player but on the other hand we have to say there have been refereeing mistakes. We’re really worried about Robben’s diving. And he admitted it. I hope the referee watches him very closely tomorrow.”

He said that the “most logical solution” might be to book Robben early in the match if he dived to try to win a free-kick. “Maybe he would have to leave the field because he gets two yellow cards for diving,” said Pinto. “Why not? That could happen. I want to trust the referees. Let’s see what happens.”

Pinto, who will lead his side into their first World Cup quarter-final, said that Costa Rica would not be overawed by facing the Dutch in Salvador and could take confidence from their performances in Brazil.

“Of course I respect them. But we have played against England, Italy, even Greece is a difficult team. We’re never scared. We respect them but we will try to control them. We know two or three Dutch players are very strong and we’ll try and control them.”

Pinto said he had studied previous World Cups before devising a strategy based on a solid defence and fluid counterattacking. Arsenal’s Joel Campbell will again lead the attack and Pinto will hope Bryan Ruiz can continue his impressive form.

“Watching older World Cups I have realised defending is very important. That’s why I wanted to build a good defensive system and attack from the back to the front,” said Pinto, paying tribute to goalkeeper Keylor Navas. “Our goalkeeper is incredible – he has played very well in Spain and for us as well.”

Pinto thanked the Brazilians for backing his side and said they would try and avenge Holland’s victory over the hosts four years ago in South Africa. “South Americans have always supported other South American teams, we’ve seen that in this World Cup,” he said. “We’ve always supported Brazil because we are brothers. It’s nice that they support us. We’ll try to win a game they couldn’t win in the last World Cup.”