Some players miss out due to injury but others just don't fit into their national team manager's plans
As with any major tournament, there are a few stars missing from the constellation of players that will be gracing the pitches of France.
Euro 2016 will go ahead without some big names with many of those like Germany's Marco Reus and Ilkay Gundogan missing out due to injury. For others, like France's Karim Benzema or Croatia's Dejan Lovren (who had fallen out with his manager well ahead of the deadline), they knew long in advance that they would not be picked, while his former international team-mate Samir Nasri is among those to have retired from duty prematurely.
Spain have such a surplus of talent though, that some major talents have been left out for reasons other than injury, retirement or suspension.
A highly-rated young left-back at Valencia, Gaya was in the preliminary squad, although he has yet to win a senior cap. He is still just 21.
A star of Atletico Madrid's run to the Champions League final, the midfield operator was unable to breakthrough a crowded queue for a Euro 2016 plane ticket.
The 21-year-old was in the preliminary squad and is definitely one for the future at his current rate of development.
A regular in Spain squads, his season at Arsenal was derailed midway through due to a knee injury which kept him out of their title run-in and ultimately it has also resulted in him missing the cut for Euro 2016.
Spain's Isco Alarcon, right, challenges for the ball with Romania's Gabriel Toje during a friendly soccer match between Romania and Spain in Cluj, Romania, Sunday, March 27, 2016. (AP Photo/Mircea Rosca)
Another silky Spanish midfielder to miss out, the Real Madrid player was in the provisional squad like Saul but his journey went no further.
The 2015-16 season at Manchester United was far from his best but an excellent attacking midfielder he remains. He already has 10 goals for his country in 41 caps.
Valencia's Paco Alcacer already has six goals in 13 games for Spain and breached the double-figure mark for his club during the season.
He was also Spain's top scorer during Euro 2016 qualifying. Yet all that was not enough for the 22-year-old who was left out of the final squad by Vicente Del Bosque.
The Chelsea striker has never truly fitted in with Spain and after an under-par Premier League season, he has been left to watch the tournament at home.
A shadow of his former self but still led the line for Atletico as they reached the Champions League final. For the first time since 2009-10, he also hit double-figures in a league season.