Netherlands vs Uruguay semi-final preview
Robben has long held a reputation as a theatrical player, and Brazil midfielder Felipe Melo said after their quarter-final meeting: "Every time he was touched he would jump and roll over on the floor."
Van Marwijk admits Robben can appear to go down under minimal contact but, ahead of Tuesday's semi-final against Uruguay, he has said he can no longer be considered a diver.
"He doesn't do it deliberately," he said. "Arjen is incredibly fast and creative. He faces up to opponents and you do fall, or get pushed.
"Maybe he has done things in the past that he shouldn't but he has learned and doesn't do it anymore."
Uruguay boss Oscar Tabarez chose to focus on Robben's quality as a player and said he will rely on the referee to spot any playacting.
"He's a great footballer," Tabarez said. "He's very fast, very nimble, very long strides. When he shifts his body it's difficult to react. With Robben back, this Holland side benefits greatly. They were already very good without him, but now they have him contributing as well.
"Like any footballer who is hit on the pitch - well, I wouldn't say he is a 'cheat'. These are things that happen in football. It's up to the referee to determine the players' intentions."
Tabarez has seen one of his own players labelled a cheat in recent days, with Luis Suarez provoking a storm after his deliberate handball prevented Ghana scoring a last-gasp winner in their quarter-final.
A Johannesburg paper on Monday ran with the headline 'You cheat' in reference to Friday's game, and Tabarez has grown exasperated by the media's response.
"I'm embarrassed by what has been asked," he told a press conference. "That is shameful.
"It was an instinctive act. Suarez couldn't foresee what happened afterwards, that Ghana would miss the penalty. Don't talk to me about a lack of modesty. We are very proud and we're upset with this topic. We're proud of our performances and what we've contributed to the development of football at this World Cup.
"Uruguay went through almost three matches without a yellow card at all, so please don't tell me we're cheats."