Barcelona have made their first signing of the summer, completing a deal for Brazilian midfielder Arthur Melo from Gremio on a six-year contract.
Barca and Gremio had originally agreed for a deal to be done next January, upon the conclusion of the Brazilian season, but a number of factors led the La Liga champions to fast-track the transfer.
The decisions of Andres Iniesta and Paulinho to leave the club opened up a space in midfield, while Yerry Mina's struggles to adapt after arriving last January left Barca sceptical about another midseason signing.
The La Liga club said in a statement on their official website that the transfer fee for the 21-year-old was €31 million, with €9m more in potential bonuses.
"The player will sign a contract with the club for the following six seasons, until the end of the 2023-24 campaign," the statement said.
Sources close to the deal confirmed that Barca had to pay an additional fee of about €1m in order to complete the transfer six months early.
"Barcelona have asked to bring my arrival forward to this summer," Arthur explained in a news conference on Friday. "I did not participate in the negotiations, nor did I participate directly in my transfer -- it has been a matter between the two clubs.
"I will probably travel to Barcelona this weekend. There are still details [to be finalised] but I'm very happy to be able to wear the shirt of the club I have always dreamed of playing for, the biggest club in the world.
"I have been told wonderful things about the club, the city and the fans. I have high expectations about the move."
Arthur joined Gremio in 2010 as a teenager and played a key part in their Copa Libertadores triumph last season.
Former Barca sporting director Robert Fernandez watched him play in the final at the end of last year and later gifted him the club's home shirt, which he was seen wearing.