Rubio, who missed most of the 2021-22 and 2022-23 seasons with the Cleveland Cavaliers recovering from a torn ACL, retired from the NBA earlier in January after he had stepped away from the franchise in August to concentrate on his mental health.
"After several weeks of thinking and dedicated work on both my mind and body, I see myself with the desire and strength to see how I react with a ball in my hands," Rubio said in a post on social media platform X.
"My next step has been to ask FC Barcelona if I could, with no obligations and without interrupting their plans for the season, train with them."
Born in El Masnou in the province of Barcelona, Rubio played 140 competitive matches for Barca from 2009 to 2011, helping them to two Spanish Cups, one league and one EuroLeague title.
