Even by Barcelona and Real Madrid's high standards, it has been a busy summer in Spain. Several high-profile players have left both clubs, with Angel Di Maria, Cesc Fabregas and Alexis Sanchez dominating that list, while the incoming players are of an equally great stature.
No less than the World Cup's best player, James Rodriguez, and the Premier League's top scorer, Luis Suarez, are now on the books at the Bernabeu and Camp Nou respectively.
Yet while those forward signings have undoubtedly caught the attention of both groups of supporters more than any other transfers, the truth is there's a significant chance they won't prove to be the most important.
Instead, it's moves for two new central midfielders that are likely to have a decisive impact on the outcome of this season's Spanish title, and neither are typical signings for Spain's big two.
In the red and blue corner stands Ivan Rakitic, 2014 Europa League winner, man of the match in the final and former heartbeat of Sevilla. In the white corner, Toni Kroos, the man who drove Germany forward to a World Cup win in Brazil, boasting a treble with Bayern Munich less than two years prior.
The strange thing is, based on their traditional standards, these two midfield geniuses could easily have been on the opposite side of the ring, punching it out for their new rivals.
Real Madrid are the perfect counterattacking machine, a group of immense athletes with killer instinct, and no midfielder is better at launching a swift counterattack than Rakitic. At Sevilla he made an art form of winning the ball back then delivering a pinpoint cross-field pass in the space of seconds.
Kroos, meanwhile, was key in helping Bayern to make the transition towards Pep Guardiola's brand of football, so successful at Barcelona. The Catalan very quickly realised Kroos' talent for thinking one step ahead of his opponents, as well as his capacity to retain the ball and add a touch of patience to affairs. As such, the Bayern boss made Kroos one of the focal points in the new look Bavarian midfield. Guardiola's former club Barcelona would, traditionally, have jumped at the chance to sign someone like the World Cup winner when made available.
Yet despite strong and trustworthy reports that the Blaugrana were offered Kroos earlier this year, they passed up the chance. More than a few eyebrows were raised as a consequence, with the prevailing sentiment being that the Catalans had ignored a perfect opportunity to replace Xavi. Especially when you consider his price tag of 30 million euros.
Equally, Rakitic made very public attempts to court Real Madrid last Easter, with some rumours suggesting Los Blancos had more or less agreed personal terms. If the interest in him was genuine, the Champions League winners must have ultimately passed on a deal, perhaps deciding they wanted a different option to the obvious one this time around.
That's the beauty of these two signings: neither are obvious choices for their respective clubs, yet both have the potential to solve some of their new teams' biggest deficiencies.
Madrid's biggest problem over the last decade has been that Los Blancos struggle to break down opponents who cede them possession. Carlo Ancelotti is more than aware of that, and tried unsuccessfully to make Madrid more proactive with the ball last season, before ultimately giving up around Christmas time and reverting to counterattacking type.
That return to the counterattack won Madrid the Champions League, but the old problems persisted domestically and eventually cost them the league title. Somewhat appropriately, Sevilla's dressing-down of the Spanish giants in a 2-1 win at the Ramon Sanchez Pizjuan last March -- with Rakitic at the heart of it all -- was the perfect example of how to stifle Madrid by sitting deep.
Equally appropriate is the fact that Kroos was once a key player for the side that exposed Barcelona's own deficiencies more than any other. Bayern Munich's 7-0 thrashing of the Catalans in the 2012-13 Champions League showed that marrying technical brilliance with physical prowess can be an almost unstoppable combination. Kroos didn't play in those particular games, but he is a perfect example of how Bayern focused on unifying the two qualities to excellent effect, while Barcelona (on the other hand) lost that type of player following the departures of Yaya Toure and Seydou Keita.
If the last few weeks are anything to go by, Barcelona and Real Madrid's respective attempts to diversify their midfields look like a worthwhile endeavour. Madrid fans were thrilled with how Kroos grabbed the European Super Cup game against Sevilla by the scruff of the neck earlier in August, with the German constantly looking to receive the ball under pressure then change the direction of play to unsettle the rigid Andalusians. Unlike in the league last March, Sevilla's attempts to stifle Madrid were fruitless; this was a whole new beast wearing white.
Rakitic, equally, has added some much-needed bite as well as a heavy dose of directness to Barcelona's game. The Croatian's capacity to win the ball back effectively in the midfield has provided security for Sergio Busquets to push forward when he sees fit, meaning Barcelona no longer look lightweight in the middle. Rakitic's other biggest strength, his eye for a first-time ball, was on show in the opening weekend of the La Liga season, when with one lofted pass he perfectly teed up Munir El Haddadi for the second goal in a 3-0 win over Elche.
The new Barcelona No. 4 isn't afraid to shoot from distance, either, nearly getting on the scoresheet in that game and showing opponents that they will now need to be wary of letting Barca take pot-shots, when in the past the Blaugrana weren't much of a threat from range. Understandably, Barcelona fans have very quickly warmed to the Croatian, who looks like he has been playing with the side for years.
Just how much these two players excel in the coming months, time will tell, but there's little doubt that they will have a huge say in their teams' respective fortunes. At the moment Rakitic has probably started better, made easier by the solid, well-established system of play he has slotted into at Barcelona. We are unlikely to see the true extent of Kroos' brilliance, however, until Ancelotti figures out just how exactly he is going to set up his team without Di Maria.
The departure of Xabi Alonso, meanwhile, places even more responsibility on the German's shoulders. The stakes couldn't be higher for Madrid's new playmaker. It's worth keeping this in mind when the first Clasico of the season rolls around in October, and inevitably all the focus is on the return of Suarez, or how James can produce another screamer like he made a habit of at the World Cup. Instead, keep your eye on Kroos and Rakitic. They will be the players who are really tasked with driving La Liga's big two forward.