La Roja suffered a 2-0 defeat against Chile last night to confirm their departure at the group stage of the tournament.
"It's hard to explain," the 26-year-old is quoted as saying by FIFA.com. "We were excited at the prospect of winning this game and carrying on in the competition but it wasn't meant to be.
"There's nothing else for us to do but try to sign off on a high note and then go home. We have to pick ourselves up. It's tough but we have to look to the future, be positive and try to take Spain back to where it belongs, which is the very top."
The victory for Chile also signalled the end of Australia's World Cup campaign, with one round of group stage fixtures still left to play.