The majority of managers will have a set idea of their preferred line-up in a variety of formations.
Whether those players start will depend on a number of factors including injuries, tactics, opposition and upcoming matches.
With the larger clubs competing in many competitions, rotation is necessary, and many managers face heavy criticism when they try to implement it unsuccessfully.
Diego Simeone has previously opted to make few changes, and it's not clear whether that's to increase the familiarity within the side or due to a lack of squad depth.
The rise of a talented group of youngsters and a number of new signings mean that the Argentine can afford to be a little more flexible with his approach next season.
The likelihood, though, is that he will establish his first-choice players and make few changes in the opening rounds in order to gather some momentum.
Atletico has let an incredible three players leave in this position, although they would have loved to retain Thibaut Courtois for a fourth year.
Miguel Angel Moya has joined from Getafe, whilst 21-year-old Jan Oblak arrives from Benfica (per Charlie Skillen of the Daily Mail).
The club has a history of helping young shot-stoppers find their feet. David de Gea earned himself a move to Manchester United prior to Courtois' spell.
On that basis, we can presume that Simeone will elect for the raw but talented Oblak.
There will be few changes to this incredible back four, with only new left-back Guilherme Siqueira replacing Chelsea-bound Filipe Luis as a regular.
The club won the league by having the meanest defence in the division, so Juanfran, Diego Godin and Miranda will continue unless there are further sales.
They certainly have options in the centre should they receive injuries with Belgium international Toby Alderweireld and young Uruguayan Jose Gimenez providing cover.
This just leaves the very left-footed Emiliano Insua as a back-up at present.
The experienced Portuguese midfielder should feature alongside captain Gabi in the centre of the pitch.
Like many players under Simeone, Mario Suarez is much improved, but Tiago started five more league matches than Suarez last term.
Koke has the ability to play in a deeper role, but he's expected to occupy one of the three attacking midfield slots the majority of the time.
His passing ability has attracted the attention of Barcelona as a replacement for Xavi, though he signed a new contract last month to keep the Catalans at bay for at least a year (via The Guardian).
Turkish winger Arda Turan had his most productive campaign to date and should kick on even further.
He needs to add more goals to his game, but his quick feet and pace are crucial to the side's counter-attacking prowess.
The final member of the attacking trio is likely to be Raul Garcia.
He registered nine La Liga goals last season in 18 starts but only managed the full 90 minutes 12 times in 52 appearances in all competitions, via Whoscored.com.
It's a tall order to replace Diego Costa, but Mario Mandzukic has the necessary attributes to fulfil the role.
The Croatian was the Bundesliga's second-highest scorer last season and netted 23 times in all competitions, via Whoscored.com.
These statistics are even more impressive when you consider that his style wasn't particularly suited to Pep Guardiola's philosophy at Bayern Munich.