Kaka has admitted Real Madrid need to combine talent with hard work if they are to fulfil their undoubted potential.
Kaka, Cristiano Ronaldo, Karim Benzema and Raul Albiol have all arrived at the Bernabeu during a dramatic summer of spending by the Spanish giants.
However, the Brazil star has warned that world-class players are only one part of a successful team.
"My experience in football tells me that talent is not enough," he said.
"The Brazilian national team in 2006 had a lot of talent, but we were knocked out of the World Cup quarter-finals because we lacked many things which prevented us from succeeding.
"Real Madrid have Cristiano and Kaka, and that's good because we are quality players, but we need to build a team and work very hard. Real Madrid won't become invincible just by signing us."
However, Kaka has set his sights on winning Europe's top prize in his first season in Spain.
"The Champions League is the most important tournament after the World Cup. It has a unique grandeur and every footballer dreams of winning it," he continued.
"I've been lucky enough to lift the cup for Milan and now my dream is to do the same for Real Madrid.
"To win it in my first year and at the Bernabeu would be incredible. I grow anxious just by thinking about it. I'd like to start playing right away."
Meanwhile, sporting director Jorge Valdano has admitted the big-spending club needs to offload several players following their summer transfer moves.
The likes of Ruud van Nistelrooy, Klaas-Jan Huntelaar and Arjen Robben have been linked with moves away from the Bernabeu following the arrivals of Ronaldo, Kaka and Benzema.
"We need money to continue being active in the market and at the moment to get money we have to sell players," said Valdano.
"We need to trim at least five players from the squad. The priority over the next few weeks is the sale of players and not the signing of new ones.
"Things are progressing with some players. But a bit of calm is needed in some cases because we have to complete the negotiations with the clubs."
Coach Ernesto Valverde has urged Villarreal to resist the temptation to cash in on Santi Cazorla this summer.
The Spain international midfielder has been mentioned as a possible transfer target for La Liga heavyweights Real Madrid and Barcelona.
The Yellow Submarine have already admitted they must operate on a vastly reduced budget next season, but Valverde hopes that doesn't lead to the departure of Cazorla.
He said: "I am not the president of the club who can talk about transferable and non-transferable players.
"Cazorla is very important for Villarreal. He is a player that can make the team tick. I would not like to see him leave."Reuse content