David de Gea (GK)

There's not much debate to be had here. De Gea is the No. 1, an undisputed and guaranteed starter.And with good reason—his form is impressive, his ceiling is as high as anyone's in world football right now, and he is consistently an elite performer for Manchester United and Spain. Top reflexes, a dominant aerial presence and good distribution make him Lopetegui's firm first-choice goalkeeper now and for years to come.

Gerard Piqué (Defender)

There's more concern over whether Ramos' long-term international partner will go to Russia, with Pique recently stating he would skip the finals if his support for Catalonia's bid for independence was seen as a problem, per BBC Sport. Assuming that's not the case, Pique will also start centre-back: an aerially proficient player who has good pace and agility and a fantastic ability to bring the ball out from the back. Like Ramos, he doesn't lie down and accept a bad result. Spain want these two on the same wavelength at the finals.

Sergio Ramos (Defender)

There is no question that Sergio Ramos will be going to the World Cup finals—as captain and starter. He will either have already clocked up 150 caps by the time the tournament starts, or he'll reach the milestone during the group stage, which is a formidable achievement. Ramos has consistency issues at times, but he's effective in both penalty boxes and is a real leader who refuses to accept defeat.

Jordi Alba (Defender)

The first two picks at full-back are straight-forward if both are fit and healthy. Right now, only Jordi Alba is, so he's included first here. Barcelona's left-back is fast, direct, hardworking, aggressive and always looking to get forward on the overlap—basically every key trait Spain need from their wide options. He's a guaranteed starter when fit, and few can replicate what he brings to the team, especially when factoring his experience at the highest club level and on the international stage, where he now has over 50 caps.

Andrés Iniesta (Midfielder)

Iniesta's name might not be a guarantee for the first XI anymore, but it's unthinkable that he won't make the squad. He probably will be in the team, too—at least to start. The Barca man still has the capacity to unlock any defence, is looking sharper and more agile when one-on-one this season and offers positional flexibility. He could play as a No. 8 as usual but also from the left in the forward line.

David Silva (Midfielder)

Another staple of the Spain squad, Silva has over a century of caps and is now one of the more experienced players in this team, a leader of the front line and a guaranteed source of chances on goal. He has played both from the sides of the attack and as a false nine in this qualifying phase, but wherever he plays, determination and invention are included. Silva's movement remains top class, and the closer he is to his best form the better Spain's chances of winning the World Cup.

Isco (Midfielder)

There are a handful of players set to make the squad who are borderline starters depending on others' form and Lopetegui's system of choice; Isco is one of those. His own run of form over the last six months or so has been immaculate, at domestic and international level, and his productivity in key games—notably for Spain against Italy—is a big factor in his favour. Real Madrid's current golden boy has to keep this level up for the remainder of the season to be a guaranteed starter in the same way Busquets or Ramos is.

Thiago Alcantara (Midfielder)

The final one of our six central midfield names is Thiago, and he's the least certain pick. That's not because of talent or form issues, though, it's down to his fitness. If he manages to put a string of games together for Bayern Munich in the final third of 2017/18, there's no question he'll be involved. So far he's started five times this season, so it's looking good. Maintaining fitness has always been the former Barcelona starlet's worry, though. Just missed the cut: Asier Illarramendi, Sergi Roberto, Cesc Fabregas, Ander Herrera

Sergio Busquets (Midfielder)

One of Lopetegui's first names on the teamsheet, Busquets anchors the midfield, protects the defence and is the platform for the attackers to run riot. His passing between the lines is pivotal to Spain's play, and with great movement ahead of him, Busquets should shine to his maximum. He is still the world's best defensive midfielder.

César Azpilicueta (Defender)

Chelsea's versatile defender will make the cut as a full-back, since he's capable of playing on both sides as well as centrally. He's probably not going to make a real push for a first-team place, as he's more a full-back option than centre-back for the national team. But he plays in the middle at club level, making a direct translation of form difficult. Even so, he is composed, reliable and a squad regular—he's sure to be on the plane to Russia.

Rodrigo Moreno (Forward)

Marco Asensio (Midfielder)

He might be Real Madrid's current icon for the future, but Asensio is already making waves in the present, too. His ability to score goals from any position in the final third is a massive factor for Lopetegui to consider, with Spain at times guilty of not making the most of openings and looking for the extra pass. Asensio hasn't replicated that goalscoring ability on the international stage just yet, but once he finds a role in this team—which admittedly might not come until after the World Cup—he'll surely become a go-to source for goals.

Coke (Midfielder)

A pair of Atletico Madrid midfielders are next in line, starting with Koke. The industrious and versatile performer can play right along the middle line of Spain's systems; he is just as adept at winning possession and creating chances from the channels as he is in the centre. Set-piece prowess is also in his skill set, and Koke can emerge to be one of Spain's most important players at the finals if he hits form towards the end of the season

Dani Carvajal (Defender)

The Real Madrid right-back is more considered, less explosive and perhaps slightly technically superior to Alba, but he fills the same role—get forward to support, deliver quality in the final third and be aggressive in defensive work. If he's fit, he'll start, but right now he's out for at least a couple of months with a virus, so it's difficult to predict how much of a setback it will be to his season. Carvajal might face an extended period of recovery, but he couldn't ask to be in a greater spotlight when he comes back: Real are as high as the domestic ladder goes, and playing well at the Santiago Bernabeu all but guarantees a place in the national team.

Iago Aspas (Forward)

The back-up forward for Spain? It's a tough one, but Aspas represents a second-striker option rather than only being a direct alternative to Morata. Aspas can play as the No. 9 by himself or just behind in a supporting role when required. His form for Celta Vigo remains good; he's a goalscorer and an inventive forward, and he has three goals in five international games. It could turn out to be a fight between him and Aritz Aduriz. Just missed the cut: Diego Costa, Paco Alcacer, Rodrigo, Aritz Aduriz, David Villa

Monreal (Defender)

Nacho (Defender)

He might be Real Madrid's third-choice centre-back still, but the truth is Nacho Fernandez is playing a more key role now than ever at club level and rarely has a bad game, either at left-back or in the middle. He's probably the fastest centre-back on offer to Spain, too, and his aggression and reliability make him a perfect stand-in if either of the first-choice defenders is missing.

Alvaro Odriozola (Defender)

The final pick here is a more difficult one, but we'll switch attention to the man who started at right-back in Carvajal's absence against Albania on Friday. Odriozola is a key performer for Real Sociedad right now and has attracted plenty of interest thanks to his top-notch performances down the side of the back line. He was linked with Real Madrid in the summer, per Marca, and if he keeps up his good form, the 21-year-old has every chance of being the final full-back pick Just missed the cut: Nacho Monreal, Hector Bellerin, Juanfran

Javi Martínez (Defender)

Lucas Vazquez (Forward)

Diego Costa (Forward)

Sergio Rico (GK)

Pepe Reina (GK)

The veteran Napoli stopper might not play at the finals, but he'll still have a vital role. Reina has long been a dressing-room leader, a man to lift spirits and encourage a togetherness among the squad, previously as understudy to Iker Casillas and now De Gea. Will he play? Is he still capable at the elite level at age 35? Well, his Napoli side are top of Serie A and have conceded only five times this season, and he's the regular starter—so ability won't be an issue. Reina might play if it's a pivotal game that De Gea is unavailable for, but if it's a group-stage dead rubber, he'll likely step aside for the No. 3 to gain experience.