Genoa snap up Rafinha
The surprise move for the Brazilian underlined Genoa's determination to break into the Serie A top four.
"The Preziosi family has decided to enrich the treasure chest with a wonderful jewel - Rafinha," the club said in a statement.
Media reports put the fee at 9 million euros.
Italy's oldest club have signed striker Luca Toni and Portugal World Cup goalkeeper Eduardo among others during an otherwise quiet transfer window in Italy.
Genoa owner Enrico Preziosi, supposedly banned from conducting club business by the Italian federation for past financial irregularities, has carried on regardless and after a mid-table finish last term he has spent some of the cash earned from selling Diego Milito and Thiago Motta to Inter Milan.
He told reporters on Wednesday that Rafinha may end up playing midfield, possibly allowing Giuseppe Sculli to move to Inter.