The Real Madrid man believes a number of current Roja players will bring their international careers to an end after the tournament in Brazil
La Roja are the reigning world and European champions and will head to Brazil as favourites for the tournament.
But with a host of young talent ready to make the step up to the national side, the Real Madrid man says it could be the right time for him and several other experienced names to hang up their boots at international level.
"After the World Cup there will be many who decide to stop playing for Spain," he told AS.
"That way younger players can come in. For that reason winning the World Cup would be a great climax. After that, it may be that nothing is the same again.
"We will be favourites at the Brazil World Cup, but although we have a great team it won't be easy to win two World Cups back-to-back like we did at the European Championship."
Casillas is Spain's most capped player of all-time with 143 appearances to his name.