When you cost your club £56million, a paltry return of just 61 league appearances in more than three years tells its own story. Injury, form and favour had conspired to limit a FIFA World Player of the Year to the margins of one of the world's most famous clubs.
However, in recent weeks the Bernabeu has been treated to tentative glimpses of the old Kaka. Trademark bursts, slide-rule passes and even the hands-to-the-heavens celebration have each made a comeback while a smile has returned to the face of the Madrid number 8.
After many false-starts, maybe now Kaka is ready to bring the form that brought him the 2007 Ballon d'Or to the Bernabeu.
For Jose Mourinho and Madrid the timing could not be better. Setting aside El Clasico humiliations, Madrid sit 10 points clear in La Liga and well-placed to make a run at the Champions League.
The Brazil international has played an important role in helping Madrid to finally usurp Barca domestically, but in Europe a fully-fit Kaka could be the difference between success and failure.
Already this campaign Kaka has made a larger contribution at this stage than in previous seasons. The Brazilian has played 32 times, scoring six and laying on 12 assists. Finally, the injury nightmare that has plagued him since leaving AC Milan may have passed.
A reoccurrence of a groin problem suffered while at Milan meant his arrival in Spain got off to a stuttering start. That was followed by a persistent knee compliant, which resulted in countless consultations and a further eight months on the treatment table. To make matters worse, his £56million transfer fee smacked of a return to the Galactico era, especially as he was signed by newly-elected Real Madrid president Florentino Perez, the man responsible for the first failed attempt to create a Real Madrid "super-team".
Perez was elected on the promise of re-establishing Madrid as a worthy opponent to Barca's all-conquering 2008-09 team. As a result, Perez opened the cheque book to sign Kaka and £80million man Cristiano Ronaldo. So far, however, all Perez has to show for his investment is a single Copa de Rey win in 2011. This looks likely to change, though, as long as Madrid hold their nerve over the coming weeks, and Kaka's re-emergence could play a crucial role in the run-in.
The South American midfielder may no longer be capable of the kind of lung-busting runs of his Milan days, but the intelligence, anticipation and technical ability remains. Back to his best against Espanyol a few weeks ago, Mourinho reserved special praise for Kaka after he turned in a man-of-the-match performance against CSKA Moscow in the Champions League.
"He had a spectacular match. He had his best games at AC Milan but he has never worked harder than now," Mourinho said. "He does fantastic work for the team and it is normal that he doesn't have enough strength in his legs after 75 minutes."
The 'Special One' had withdrawn Kaka with 15 minutes to play, allowing a raucous Bernabeu the opportunity to salute a fantastic performance. Orchestrating a fluid Madrid midfield, Kaka laid on the first goal for Gonzalo Higuain before a Ronaldo brace and a Benzema tap-in sealed a 4-1(5-2 aggregate) win for the Spanish side.
Their Russian opponents had actually started quite brightly but on Champions League night's like this, Madrid were always going to pull through. Los Blancos have now won 31 of their last 35 matches and, along with Barcelona and Bayern Munich, are the team others want to avoid in Friday's Champions League quarter-final draw.
The team finally seems to have a better balance. With Xabi Alonso and Sami Khedira screening the defence, Kaka and Mesut Ozil are given greater creative license. As with all Mourinho teams, organisation and structure remains crucial to success but, with Nuri Sahin and Esteban Granero largely left on the bench, the Portuguese coach recognises that Kaka's quick feet and sharp mind could hold the key to unlocking better defences further into the competition.
A return to the top for Kaka is not just good for Madrid, it's good for football. Generally regarded as one of the game's nice guys, injuries have robbed him of too much playing time already. The group of world-class players at the top of football has always been a relatively small club. Kaka, briefly in 2007, played with such quality that many regarded him as the world's best, but age and injuries have meant he's since fallen from this level.
At 29 years old we may never see him reach his peak again but it is doubtful if, in the same team as Ronaldo, he would ever see the ball enough to dominate games as he did with Milan. Instead, he is a very effective part of a very good team. Barring injury, with Kaka back to his best, Madrid stand the best chance of ending Barca's monopoly on trophies.
Pep Guardiola's remarkable run has seen him win 13 of a possible 16 trophies since taking over at Barcelona. So far, Bernd Schuster, Juande Ramos and Manuel Pellegrini have failed to halt the Catalan's rise. Mourinho began to claw back some pride with a Copa del Rey victory last season but Barca still stole off with the big prizes, namely a Champions League and La Liga double.
For a club like Madrid, such dominance by their closest rivals has been difficult to take. For Mourinho, success this season equals domestic or European glory, possibly both in the eyes of some fans.
Without Kaka, Madrid should still wrap up La Liga relatively easily. With him however, they just might win the Champions League as well.