When his world record signing was then eclipsed by that of Cristiano Ronaldo later that same summer, the club looked set for a period of domination, with the expensively acquired pair lighting the path to glory.
That prediction, of course, was half true. Real Madrid have since gone on to win trophies, even if they may have initially hoped for more, and Cristiano Ronaldo has, indeed, been at the heart of their recent successes. For Kaká, though, the story has not been so idyllic.
Consigned to the role of occasional substitute, Kaká has spent the past month looking for an exit route out of the Bernabeu.
A dream return to his former home at AC Milan fell through over Real Madrid's high valuation of the player (via Independent), while it appears that his only hope of a late escape this month may arrive in the unlikely form of Russian side Anzhi.
In just three-and-a-half years, Kaká has gone from footballing superstar to non-event. A player who once offered almost unparalleled elegance and grace is now consigned to a bit-part role that has seen him once more lose his position in the Brazil national side this month.
Kaká's time in Madrid began on a positive note back in 2009, with the Seleção star posting a reasonable return of eight league goals in his first campaign. Making just 25 appearances due to niggling injuries, it was a reasonable if unspectacular adaptation to his new Iberian surroundings.
However, it was to be the 2010 World Cup, at the end of that first season in Madrid, which would have a long-lasting effect on the now 30-year-old playmaker's future.
Returning from the competition with a knee injury, Kaká was forced to undergo major surgery that would radically shorten his 2010-11 season (via Goal.com).
The injury would mark a turning point in the Brazilian star's Real Madrid career. In his absence, the club had quickly moved to bring in World Cup stars Angel di Maria and Mezut Ozil—both of whom quickly settled into the team, as Kaká could only watch on from the sidelines.
Upon his return, though, the 2007 FIFA World Player of the Year was in scintillating form. Finishing the 2010-11 season with seven goals in 14 games and beginning the following campaign in similar style, there was a growing feeling that Kaká was finally returning to his glorious best.
Come November and the surge in support forced a breakthrough. After nearly eighteen months of post-World Cup isolation, Kaká was finally recalled to the Brazil squad.
Predictably, though, within days of the announcement being made, his fine run was ended, as a calf strain forced his withdrawal from the squad.
It was back to square one for Kaká after his promising start to the campaign and, although he would appear 27 times as Real Madrid went on to left the La Liga title, the Brazilian would manage a full 90 minutes on just four occasions throughout the entire season. Real Madrid's patience was beginning to wear thin.
Reports at the time indicated that the once world record signing was offered out on loan last summer, while his lack of significant playing time since would suggest that may well have been the case.
Internationally, Kaká enjoyed a brief renaissance earlier this season, as a key member of the Brazil side in the final days of Mano Menezes' tenure. Goals against Iraq and Japan followed, but it was not enough to save Menezes' job or to push Kaká's claims at club level.
And so, in this tale of misfortune and poor form, we arrive at the present time. Kaká's Real Madrid career would appear to be on the ropes and, following the ascension of Luiz Felipe Scolari to the Brazil throne, with it his international ambitions.
Kaká knows he must act quickly to fulfil his dream of representing Brazil in a World Cup at home next summer, but a return to either Brazilian domestic football or AC Milan is not currently financially viable.
It may well be that Anzhi, as previously mentioned, is the only answer to end his Madrid nightmare. However, a journey to the Dagastani outfit is unlikely to significantly boost his hopes of a Brazil recall. Thus, a difficult decision awaits for the Brazilian icon.
In the context of his Madrid disappointment, though, it may just be that a once unthinkable move to Russia has now become a risk worth taking.