Oh, that story...
Aldo Kuerten was referreing a match back in Santa Catarina, and he died of a heart attack.
Some time before he died, he asked his friend Larri to coach his son Guga, who he thought would have a bright future. But only if he had the best one around to coach him. Passos said to Aldo that Guga was still too young, but that he would contact the boy as soon as he thought he could start.
He kept the promise, and when Guga was around 14 or 15, Larri went to him and revealed Aldo´s will. That mission made the two almost like father and son, and that tight relationship is indicated by both of them as one of the main reason of their success.
I hope that helps.