Former Brazil coach Luiz Felipe Scolari has tipped Arthur to be a success at Barcelona.
Earlier in 2018, the Catalan giants confirmed that the young Brazilian had been signed ahead of next season having impressed for Gremio.
Scolari worked with the 21-year-old during the early stages of his career, and feels that the midfielder is a suitable replacement for Andres Iniesta.
The 69-year-old told Mundo Deportivo: "I was the technician who gave Arthur his debut with Gremio. Arthur is a player with characteristics similar to Iniesta.
"These last two years he had improved a lot with Renato Gaucho as coach. I am very happy with his signing for Barca. I think he will fit in very well."
Iniesta is currently being linked with a move to the Chinese Super League.