Benfica midfielder Ramires is in London for a Chelsea medical today.
BBC Sport says the 23-year-old is undergoing a medical at the Premier League club.
It is thought a four-year deal for Ramires, who has 16 caps for his country, could be concluded by the end of the week. He will move from Benfica for £17 million.
The transfer of Ramires, whose full name is Ramires Santos do Nascimento, has been reportedly complicated by the fact that Benfica only own a 50% stake in the player with a British-based businessman owning the other 50%.
