The Bayern Munich star feels the experience of the injured Hamburg player will be missed and says he is confident Louis van Gaal's new 5-3-2 system will work at the World CupArjen Robben says he is disappointed that Rafael van der Vaart is unavailable for Netherlands at this summer's World Cup.
The Hamburg star had to withdraw from Louis van Gaal's team because of a calf injury he picked up during a training session on Tuesday at Netherlands' camp in Portugal.
Robben, Wesley Sneijder and Van der Vaart were the only players who had represented the Oranje in each of the last five international tournaments.
Van Gaal announced his final 23-man squad for Brazil on Saturday, a team made up of a healthy mixture of youth and experience as they head into a group with Spain, Chile and Australia.
And Robben feels his former Real Madrid team-mate's absence is a big loss for the side.
"Yeah, I would have preferred that he had gone, with all his experience," he told NOS. "It will also be a huge disappointment for him.
"I have not spoken to him about it, that's a pity. With Wesley Sneijder now I'm the only player who is going into a sixth finals tournament.
"Experience is always good to have around, especially in a big tournament.
"But that's mainly mentally. Playing football is all about everyone playing the way we want to play. Do your job, it does not matter whether you're 22 or 32. You just have to do what is asked.
"I've noticed that some guys are in different stages of their careers and lives than me."
Van Gaal is implementing a 5-3-2 system into the Dutch squad for the finals instead of the usual 4-3-3, but Robben says he has a lot of confidence in the new formation.
"This system provides more stability and certainty. I really feel we're going in the right direction.
"This is an eager group."