Spain skipper Sergio Ramos has urged his teammates "to be calm" following their thumping 6-1 win over Argentina on Tuesday evening.
Despite making minimal impact in their last two major tournaments, Spain are considered among the favourites to go all the way in Russia and become world champions for a second time.
Ramos is wary of the favourites tag, though, and has warned those selected in Julen Lopetegui's final squad not to get carried away by this latest result.
"We have to be calm because we haven't won anything yet," he told reporters. "But logically it is the best way to get to the World Cup, with these good feelings.
"For us these games are not friendlies at all and everyone could see this in every [passage of] play and in the result. We have to keep this ambition but without being arrogant. We have a World Cup coming and we do want to play a very important role."
Spain face Portugal in their Group B opener on June 15, before taking on Iran and Morocco.