The 25-year-old is still contracted to Barcelona, but joined Inter on loan during the January transfer window, and has since made 10 appearances for the Italian giants in all competitions.
Rafinha has said that he is "very happy" in Milan, and is currently "learning Italian" as he targets a long-term stay with Luciano Spalletti's team.
"I'm very happy to be here, everything is going well," Rafinha told Premium Sport. "I'm playing, and that's important because it allows me to grow and find the right rhythm to reach top condition.
"I've been confident from the first day, Inter is a great team and we have the chance to reach our objective [the Champions League]. I'm learning Italian, I want to stay here. I wanted Inter right away, I feel at home here and I'm happy."
Rafinha found the back of the net seven times in 28 appearances for Barcelona last term, but he missed the tail end of the campaign with a knee injury, and did not feature in the early stages of the 2017-18 season.