We all know about the myriad talent the Spanish national side have at their disposal. With depth in every department, it's only natural that the reigning World and European champions won't have a place for every talented Spaniard playing in Europe.
With 23 places up for grabs, we look at five players—based on the season so far—who might not be making the trip to Brazil.
Roberto Soldado's actually had a good year for the most part—he ended his final season at Valencia with 30 goals in 46 games. He was also called up for the Spain squad for the Confederations Cup and scored a great goal when he was given the full 90 minutes against Uruguay.
The £26 million move to Tottenham that followed hasn't exactly gone to plan. Of course, the former Valencia captain has scored 10 goals in 19 games so far; however, five of them were penalties and five were also scored in the Europa League.
Of course it is difficult, but I certainly don’t think that a change of country and a new language is any excuse whatsoever for not performing at the level that I expect of myself. I think that I’ve been here for long enough now to have a good understanding with my team-mates during a game which is the most important thing and let’s hope that from now on you will start to see another Roberto Soldado.
If things don't improve, Soldado could be watching another international tournament featuring La Roja from home.
The former Valencia man only played three minutes in Euro 2012, and while he started the Confederations Cup final that La Roja lost 3-0 to Brazil, Mata only played 141 minutes for the duration of the tournament.
Ever since the arrival of Jose Mourinho as Chelsea manager, Mata has found himself on the bench, with more hard-working players such as Oscar and Willian preferred.
If Mata doesn't find his way back into the team, he could be relinquishing his place in the national team having only featured thrice in Spain's last seven games.
And with players like Jesus Navas, Koke, Pedro and David Silva in form, it looks like that might be the case.
Spain's all-time top scorer could miss out on a chance to help Spain retain the World Cup he helped to win. Now 32 years old, David Villa—who scored five goals in South Africa—has slowly declined ever since a leg break sustained in late 2011 while playing for Barcelona.
Having missed Euro 2012 as a result, Villa returned to action only to become out of favor for the Catalans before participating sparingly in Spain's Confederations Cup campaign, having played only 136 minutes.
A move to Atletico Madrid this past summer has offered more game time for the former Valencia striker. However, with only 10 goals in 23 games this season, Villa needs to step up his game, especially given the form Alvaro Negredo and club teammate Diego Costa are in.
And with Costa now eligible to play for Spain, Villa will have no choice but to try and outshine his teammate. Spain manager Vicente del Bosque said in a recent interview that Costa has increased competition in the squad, according to Inside Spanish Football.
And like David Villa, Chelsea striker Fernando Torres will have to up his game if he wants to remain in World Cup contention. Having suffered one of the biggest declines as a player, Torres has still made the Spain squad in their last two international competitions.
However, with competition for the striker spot bigger than ever, Torres will need more than his past reputation to help him be on the flight to Brazil.
An interesting statistic shows that out of all the Spanish strikers in contention for the national team, Torres has the least goals this season in all competitions, with six so far.
If El Nino's tally of two league goals in 14 games so far this season doesn't change, he could be another who'll end up watching La Roja from home.
Barcelona captain Carles Puyol is one of the more likely candidates to miss out on the World Cup. The 35-year-old who helped Spain win Euro 2008 and the 2010 World Cup is coming toward the end of his career, having been plagued with injuries the last few seasons.
With only 28 appearances in all competitions since the start of the 2012/13 season, it is thought that the defender may be considering retirement as he struggles to gain fitness.
With Raul Albiol now playing regular football and the rise of Javi Martinez, who can play at the back, Spain might not need to call up Puyol even if he is fit. La Roja did just fine without him during Euro 2012, with a partnership of Gerard Pique and Sergio Ramos.