The Mali-born Keita is entering the final season of his contract. Barcelona did not say where Keita would be playing next, although Spanish media reports said he was close to signing with Chinese club Dalian Aerbin.
The 32-year-old defensive midfielder was part of the Catalan club's most successful run of form after joining from Sevilla in 2008 as the club's first signing under coach Pep Guardiola. Barcelona went on to win 14 trophies over his four seasons, including a pair of Champions League titles and three straight Spanish leagues.
Guardiola stepped down at the close of the season with assistant Tito Vilanova replacing him.