The young Spain players at the heart of coach Luis Enrique's new-look side make their global debut on Wednesday when they face the experienced veterans of Costa Rica in their Qatar World Cup opening match.
With captain Sergio Busquets the lone survivor of the Spain team that won the 2010 tournament in South Africa under then coach Vicente del Bosque, Luis Enrique has blooded a new generation of players in preparation for Qatar.
Three years into the restructuring of the national side after dismal showings in Brazil in 2014 and Russia in 2018, there are signs that the former Barcelona and Real Madrid star is building something that will be a force for years to come.
Barcelona midfielders Pedri, 19, Gavi, 18, plus their Catalan club teammate Ferran Torres, 22, are three of the young faces in the fresh-faced Spain side.
Luis Enrique - who led the Reds to the semi-finals of the Euros last year where they were eliminated by Italy on penalties - has picked 14 players aged 25 or under, and the average age of the squad is the third youngest among the 32 teams in Qatar.
"We are a team with a lot ahead of us, we are very young," Torres told reporters on Sunday.
Asked whether he felt the team was obliged to prove themselves by finishing in a strong position in the tournament, Torres stressed Spain remained a work in progress.
"We're not obliged to finish in any place. We will simply play the best we can to get results and if we can we will keep going. If we don't get the results, we will go out with our heads held high and keep working. We are young."
For Costa Rica, playing in their sixth World Cup, the picture is almost the complete opposite.
Six of their squad members were part of the 2014 campaign, when Costa Rica qualified from a "Group of Death" at the expense of Italy and England, and they are all now aged 30 or over, including striker Bryan Ruiz who is 37.
Colombian coach Luis Fernando Suarez's team are known for their solidity - they conceded only eight goals in qualifying - and for their ability to counter-attack, potentially posing a threat to Spain's 33-year-old defender Cesar Azpilicueta if he starts.
But the age of some of Costa Rica's core players will pose challenges beyond the physical demands of the game. Goalkeeper Keylor Navas has not played a competitive game for his club Paris St Germain in five months after losing his place to Italy's Gianluigi Donnarumma.
Spain and Costa Rica are playing in Group E along with Germany and Japan.
