Barcelona midfielder Arthur Melo will join Juventus at the end of the season in a transfer worth €72 million, plus a further €10 million in variables, the Spanish club announced on Monday.
Juventus' Miralem Pjanic is expected to go the other way in a separate deal, allowing both clubs to boost their profit figures ahead of the end of the financial year on 30 June.
Arthur and Pjanic will remain with their current teams until the end of the 2019/20 campaign, which will include the reformed Champions League knock-out stage in August.
It raises the possibility that Arthur and Pjanic could face each other, and their future clubs, in the competition's latter stages.
"FC Barcelona and Juventus have reached an agreement for the transfer of the player Arthur Melo. The Italian club will pay €72 million, plus €10 million in variables," Barcelona confirmed in a statement.
"The player will remain at FC Barcelona until the official competitions for the 2019/20 season end."
Arthur only joined Barca from Brazilian side Gremio in 2018 and was hailed as a future star for the club, with many tipping him as the long-term successor to Xavi Hernandez in central midfield.
After an encouraging start, the 23-year-old has been one of several players to stagnate this season but the primary motivation for Arthur's sale is thought to be financial.
His departure puts more scrutiny on Barcelona's board and president Josep Maria Bartomeu. They have overseen a number of haphazard moves in the transfer market and have been accused of failing to implement any clear sense of direction for the club.
Barcelona have been hit hard by the three-month suspension due to the coronavirus pandemic and they needed to bring in around €70 million to satisfy their budget for the current season.
By selling Arthur, the board can register the profits from the transfer immediately before spreading the payments for Pjanic over the length of the 30-year-old's contract.
Last year, Barca carried out a similar transaction by exchanging goalkeeper Jasper Cillessen for Valencia's Neto, in deals worth around €30 million each.
Pjanic is expected to cost around them around €10 million less than the amount Juventus have paid for Arthur but given the Brazilian is seven years younger, the Italians might feel they have the better deal.
Arthur had been reluctant to leave Camp Nou and even released a statement in April, insisting his "idea was clear" and that he wanted to play at Barcelona "for many years".
But Arthur was persuaded to change his mind after being given limited game time under Quique Setien while Juve coach Maurizio Sarri had reportedly made it clear he would be a key figure in his side in Turin.
Arthur has played 72 games for Barcelona, including 46 in La Liga and 13 in the Champions League.
Setien said in a press conference on Monday that the playmaker had promised to give his all for the rest of the season as Barcelona look to make up a two-point gap on Real Madrid at the top of the table.
"We expect the greatest commitment from him until the last day he is here," Setien said. "He is still a Barcelona player until the end of the season and has promised that he will give everything to achieve the goals we have set. He is a guy who will be committed until the last day."