Arthur and Miralem Pjanic have reportedly signed their contracts with Juventus and Barcelona, respectively, with both teams expected to make an official announcement regarding the midfielders on Monday.
Arthur has signed a five-year contract to join Juventus this summer after completing a medical in Turin on Sunday.
The Brazil midfielder has agreed to continue playing for Barcelona for the rest of the season - including in the Champions League this August - before joining the Bianconeri ahead of next term.
According to Sky in Italy, Arthur flew into Italy on Saturday night just hours after his appearance as a late substitute against Celta Vigo.
The Brazil international then flew straight back to Spain and will resume training with Barca ahead of their match against Atletico Madrid on Tuesday, with his £72.5m transfer to Italy all-but officially announced.
Juve's 30-year-old midfielder Miralem Pjanic, who will head to Barcelona for a deal in the region of £60m, also completed a medical in Turin on Saturday.
The Catalan giants have been targeting Pjanic for some time, but the deal was held up as Arthur was initially reluctant to make the move to Italy.
Arthur has made 72 appearances for Barcelona since joining from Gremio in the summer of 2018. The Catalan giants viewed the midfielder as a key part of their first-team squad, but it was reported last month they would be open to selling the 23-year-old should the right offer arrive.
Pjanic, meanwhile, has been a regular in the Juventus line-up, making 36 appearances in all competitions this season for the Turin giants, who are on the brink of a ninth successive Serie A title. They currently sit four points clear of Lazio at the top of the table with 10 games remaining.