Ramires seals Chelsea switch
The 23-year-old, who helped Benfica win the Portuguese title last season, has completed a medical after being granted a work permit, said the club website.
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"Every player in the world would love to play for Chelsea and it's a great opportunity that was given to me. I will give my best to repay this chance and I am very happy," said Ramires, who will start training with Chelsea next week.
The Brazilian is Chelsea manager Carlo Ancelotti's second major signing of the close season after Israel midfielder Yossi Benayoun joined the club from Liverpool.