The midfielder has undergone knee surgery twice in 2017 after injuring the internal meniscus in his right knee against Granada in April.
Rafinha returned to first-team training this month and Barcelona confirmed on Monday that the 24-year-old has been given the medical all-clear.
While unlikely to start against Madrid in Saturday's first LaLiga Clasico of the season, Rafinha could at least earn a place on the bench, with head coach Ernesto Valverde facing other injury concerns.
Barca will be without Paco Alcacer after the forward was injured in Sunday's 4-0 thrashing of Deportivo La Coruna.
Ousmane Dembele is not expected to be fit enough to be included in the squad as he continues his recovery from a hamstring injury.
Captain Andres Iniesta has also only recently recovered from a calf problem, although the 33-year-old managed 56 minutes of the win over Deportivo.
Barca head into the match at the Santiago Bernabeu with a six-point lead over Atletico Madrid at the top of the table, while champions Madrid are nine points behind.