Luiz Felipe Scolari has backed Arthur to become Andres Iniesta's long-term replacement when he swaps Gremio for Barcelona.
Scolari gave Arthur his professional debut in 2015 and has watched from afar as the midfielder has gone from strength to strength.
Arthur established himself as a first-team regular last season and his performances brought interest from Europe's top clubs – including Chelsea and Atletico Madrid.
However, it was Barca who won the race for his signature and Arthur will move to Camp Nou in January 2019 after the Catalan giants agreed an option to sign him for €30 million.
Scolari has backed the 21-year-old to make a big impression in La Liga, even suggesting he can step into the void left by Iniesta when the playmaker eventually steps aside.
"I was the technician who gave Arthur his debut with Gremio," the former Brazil boss told Mundo Deportivo . "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."
Arthur’s compatriots Paulinho and Philippe Coutinho are also at Barca, with the former having played under Scolari at Guangzhou Evergrande before leaving for China for Camp Nou last summer.
Scolari added: “Paulinho has another style, but he fits into Barcelona perfectly.”
Coutinho, meanwhile, completed his long-anticipated move to Barca from Liverpool in January, and Scolari feels the playmaker is another astute signing.
He said: “He is a footballer who plays in different positions, who has lots of qualities – shooting, passing, getting the ball back.
“He’s a skilful player with class, he’s another great signing for Barca.”