Rafinha is set to extend his contract with Barcelona to 30 June 2020, with the new deal including a buyout clause set at 75 million euros (£53.5m).
The Brazil midfielder, 22, rose up through the youth ranks and then spent the 2013-14 season on loan at Celta Vigo, where he was managed by current Barca coach Luis Enrique.
Rafinha won his first caps for Brazil in September 2015.
He is currently out with a knee injury he suffered against Roma in September.
Rafinha's brother, Spain international Thiago Alcantara, plays for Bayern Munich.