Barcelona will be without Arthur for Sunday's LaLiga match against Villarreal.
The Brazil midfielder has established himself as a key member of Ernesto Valverde's side this season since joining from Gremio.
But an adductor problem forced Arthur to sit out Wednesday's Champions League win at PSV and he missed Barca's final training session before their weekend encounter on Sunday.
A statement on the club's official website read: "The session was conducted on the Tito Vilanova pitch of the Ciutat Esportiva, but without Arthur who still has discomfort from overloading his adductors."
Arthur joins Sergi Roberto (hamstring), Luis Suarez, Samuel Umtiti and Rafinha (all knee) among Valverde's recent injury victims.
Barca are a point off LaLiga's summit in second behind Sevilla, who travel to Alaves on Sunday.
, ruled out for More info December 1, 2018
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