Barcelona midfielder Rafinha is expected to be out for six months after under going knee surgery.

The 22-year-old midfielder suffered a torn right anterior cruciate ligament during last week's 1-1 Champions League draw at Roma.

A statement on Barcelona's official website on Tuesday confirmed Rafinha had undergone a successful operation and that he will begin a lengthy rehabilitation.

The statement read: "According to the club’s medical services, Rafael Alcantara, 'Rafinha' has been operated successfully on by doctors Ramon Cugat and Ricard Pruna following the cruciate ligament right knee injury that he suffered in the game against AS Roma. 

"The player is expected to be out for around six months."

Barcelona is unable to field any new signings until January 2016 as a result of its FIFA-imposed transfer ban. 

According to multiple reports in Spain, in light of Rafinha's injury, Barca is attempting to fast-track Arda Turan's registration. The Turkish midfielder was an offseason signing from Atletico Madrid.