"I am pleased that Ramires has joined a top European club," said Kaka. "But I actually think it's pretty scary for the Premier League and for teams who are looking to win the European Cup this season.
"For me there is no doubt that Chelsea have signed the very best young central midfield player in the world.
"Not only is Ramires a great player but he is a humble boy and is always willing to listen and learn from those that have been in the game a long time."
And in a chilling warning, Kaka told the Daily Star Sunday: "Frank Lampard still probably has another two years left at the top and I am sure he can be a great mentor to him.
"Those two can form a devastating partnership that nobody in the Premier League will be able to cope with. Ramires is the complete central midfield player. He can tackle, pass, he works hard, he is strong and he can score goals.
"He will make the Chelsea midfield look frightening.
"At such a young age, Ramires plays with no fear and playing at such a big club and in such big games won't trouble him."
Kaka added: "I don't see anybody stopping Chelsea making it two Premier League titles in a row."