The relationship between Arthur and Barca has soured in recent weeks to the point that he no longer wants to be involved in the club's Champions League campaign, which resumes against Napoli on Aug. 8.
Barca's players underwent the latest round of coronavirus testing on Monday ahead of Tuesday's return to training to plan for that last-16 second-leg game (they drew 1-1 in Italy). However, Arthur did not turn up and sources said that he doesn't want to be involved in the preparations and would prefer that his Camp Nou stay ended immediately.
Arthur, 23, did not feature in any of Barca's final six games after the Juve deal, which is worth a potential €82 million, was announced on June 30.
At the time, Barca said Arthur would remain available for selection for the rest of the season, as would Miralem Pjanic for Juventus, who is moving in the other direction for €60m.
However, the Brazil international has grown frustrated by his lack of game time since the deal was confirmed. He wasn't among the substitutes for the final league game against Alaves, despite Barca having only three outfield changes.
Coach Quique Setien said Arthur claimed he had an ankle problem but the Catalan club did not release a statement regarding any injury, which is customary when players miss matches with fitness issues.
Setien had previously said that Arthur would play for the club again only if it was absolutely necessary.
That could have been the case against Napoli, with midfielders Sergio Busquets and Arturo Vidal both suspended, but the emergence of Riqui Puig has further pushed Arthur down the pecking order, making it highly unlikely he features again before moving to Italy.
Given the situation, an aggrieved Arthur wants to end his Barca career now. The club are in talks about how to handle the situation. They could yet take action against him for breach of contract if an amicable solution is not reached and he doesn't return to training this week.
Arthur joined Barca from Gremio for an initial €30m in 2018 and was soon compared to club legend Xavi Hernandez. However, injuries and inconsistent form saw him lose his place in the team at times this season.
As the club looked to bring in money to meet financial deadlines by June 30, they were prepared to listen to offers for the midfielder and eventually struck a deal with Juve in May.
At first, Arthur insisted that he wanted to stay at Barca but eventually had his mind changed, with sources telling ESPN that Brazil teammate Daniel Alves was among those who convinced him to make the move to Turin.