Barcelona have announced an agreement with Inter Milan over the loan of Rafinha for six months, the La Liga leaders announced Monday.
The loan will end on June 30, 2018, however, Inter will have the option to purchase the midfielder for €35 million with another €3m in incentives.
Inter will need to confirm their intent to buy before the end of the loan and have taken on all of Rafinha's salary for the remainder of the season.
"I'm really happy, it's a great feeling to be here," Rafinha told Inter TV.
"It's an important stage in my life and I had a lot of desire to approach this new phase in my career.
"There have been a lot of important players at Inter who have made history. I want to do my best and give everything to finish as high as possible and win titles with this shirt.
"I hope to play in as many matches as possible and help the team to reach our objective which is Champions League qualification."
The 24-year-old Brazilian midfielder has not played in a single La Liga contest this season for the club due to knee problems after playing in 18 last season, with 14 starts.
Rafinha only made his first appearance of the season in the 1-0 Copa del Rey quarter-final first-leg loss to Espanyol last week.
Barca's club-record signing of Philippe Coutinho from Liverpool, along with last year's arrival of winger Ousmane Dembele, further limited chances in Ernesto Valverde's first team for Rafinha, who progressed through the club's youth system along with brother Thiago Alcantara, now at Bayern Munich. Rafinha made his debut in 2011 after having signed with the club at age 13.
Valverde had recently conceded Rafinha was on his way out at the club, admitting to the media the midfielder had permission from the club to sort out his situation.
“I spoke to him about his injury and my opinion was that he needs to play minutes and in Barcelona it would be complicated after our last market movements," Valverde said Saturday.
“Our idea is to let him to play after a long time off and if he played against Espanyol it was because I thought he could help.”
Previously, Rafinha went on loan with Celta Vigo in the 2013-14 season, scoring four goals in 34 appearances in La Liga that season. He scored his La Liga high last season with Barcelona, scoring six times for the club and adding two assists.