Euro 2016: New Spain, young and unsettled

All things must pass. A Spain side that has excelled in this particular aspect of football will look to start afresh when they begin their quest for an unprecedented third straight European championship, but more importantly, the sense of invincibility that has seen them dominate world football like no other team in the past decade.

Stripped of their aura after a humiliating first-round exit in the World Cup two years ago, the defending champions have been forced into a state of evolution ever since, desperate to recreate some of the magic. While they qualified for Euro 2016 by topping Group C ahead of Slovakia with nine wins and only one loss, they have come off as merely efficient, rather than effervescent.

With an ageing squad whose strings continue to be pulled by pass master

Andres Iniesta

, following the retirement of his Barcelona teammate Xavi among others, Spain have had to patiently endure the blooding of youngsters. It is a process that has left coach Vicente del Bosque unsure of what exactly constitutes his strongest side ahead of his next major challenge.

Spain's problems with this uncertainty cuts across all departments. Skipper Iker Casillas is not the same goalkeeper who inspired confidence that he did in past triumphs. Such has been his steady decline that he became a forgotten man for his club Real Madrid and moved on to ply his trade in Portugal. In many ways, his slow downfall has reflected his national team's fortunes. The emergence of Manchester United's gifted shot-stopper David de Gea has further highlighted the Porto goalkeeper's frailties and the national coach will have a tough call to make ahead of their tournament opener against Czech Republic on June 13.

In defence, the volatile Sergio Ramos is still viewed as the best man for the job and that in itself tells a story. Having made the cut into the 23-man squad late on, seniority could ensure the 30-year-old Real Madrid defender will call the shots partnering Barcelona's Gerard Pique. Injuries to either and Spain will be forced to rely on Mikel San Jose or Hector Bellerin, both worryingly thin on international experience.

While the Barcelona duo of Iniesta and

Sergio Busquets

apart from Cesc Fabregas - despite a woeful campaign with Chelsea in the English Premier League - are perceived as automatic choices in midfield roles, the reigning champions will have to take chances with Atletico's Koke and

Bayern Munich

's Thiago Alacantara at some point and entrust them with greater responsibilities. The former has the big-match experience after guiding his side to the Champions League finals twice in the past three years.

Up front, Del Bosque surprisingly left out his top-scorer in qualifying Paco Alcacer, the temperamental Diego Costa and a resurgent Fernando Torres in favour of 35-year-old Athletic Bilbao striker

Aritz Aduriz

, who scored 36 goals in the past season, Celta Vigo's Nolito and Juventus' Alvaro Morata.

Morata is likely to get the nod ahead of his teammates despite scoring just 12 times for his club in 2015-16, there will be major concerns about where the goals will come from. Failed experiments with a midfielder playing as a false striker are unlikely to be repeated this time around.

Championship-winning squads are often built around a solid spine, something Spain have yet to settle on. A definitive style of play is another key component and while La Furia Roja have struggled to live up to the high standards of tiki taka they have set for themselves in the past, there is little evidence that they can be fluid enough to attempt a counter-punching approach. It is unlikely, though, that Del Bosque will tweak his system in a tournament that is likely to be his final hurrah.

One immediate challenge for the team management will be to motivate a team that has won practically everything international football has to offer. Conversely, how will they get a bunch of emerging players to emulate and gel with a golden generation that has fulfilled every bit of its promise at the world stage? Spain's relevance in world football cannot be doubted, but the answers to these questions will reveal the direction in which they are heading. "I will be content if we get to the semi-finals," admitted the GROUP coach recently.