Vlaar, nicknamed 'Concrete Ron' by Villa fans, has been an impressive performer since arriving in England in the summer of 2012 despite frequent injuries.
Lambert is certain his skipper will be selected by Holland for this year's showpiece and, with just one full year left on his contract, hopes to sign Vlaar up long term before he heads to South America.
"He'll definitely go to the World Cup," said the Villa boss.
"He has played in the last few games for them. He'll go and has been playing well for us. When he's not played it's been a bit of a blow because he gives us that balance.
"But he'll definitely go to the World Cup. I tend to speak to the players before they go away for the summer anyway, it's always the case.
"Myself and Ron haven't spoken about anything, I think he's been happy playing.
"His form this year has been really good. Going to the World Cup is a big carrot for him. I'm pretty sure (the contract) will take care of itself.
"Going into the last year of his contract, you have to look at it."