"Is the intensity of the FA Cup final ideal preparation for a World Cup game? Yes, I think so," said Carra.
"The FA Cup is fought out every year and the World Cup takes place every four years - but who knows when you're going to be in an FA Cup final again?
"In a World Cup game, if there's 20 minutes to go and the score's not going right, you know it could be another four years before you get another opportunity - and some players at the end of their careers may never get the chance again.
"It does then become a life and death thing where you've just got to give it everything - and credit to us at the weekend, with how many players down with cramp and yet we kept going and got there in the end.
"That's probably what you need in a World Cup. There are times when it's going to be tough and you are going to be up against it but if England are going to win this World Cup it's not going to be easy.
"It's going to be tough at times and you will have to bite the bullet.
But I do think you need that resilience, going through that pain barrier when things are not easy in order to get the rewards everyone wants for the country.
"Of course, it doesn't always work out. Who knows how it will work out against better opposition? Obviously, great respect to West Ham who played ever so well, but we were probably expected to beat them."