Barcelona manager Ernesto Valverde praised Arthur for the way the Brazilian midfielder has made a seamless transition into a key player having only joined from Gremio at the start of the season.
"He's a player who has some characteristics that fit well with the team," the coach said. "Maybe he would've had more difficulties in other teams.
"He's done very well here. He came from playing too many games, had a long-term injury last season, then playing in the national team.
"His career has taken a turn here and we hope for even more from him."
Despite some injury trouble, Arthur, 22, has made 39 appearances across all competitions this season, including 24 LaLiga matches (17 starts) and tallied one LaLiga assist.