The Spain international was taken off on a stretcher following a heavy challenge from Enzo Perez in the first half of Saturday’s LaLiga match with Valencia.
Iniesta appeared to jar his right leg as Perez slid in with a robust tackle after 14 minutes at Mestalla.
The midfielder immediately signalled to the bench as he clutched at his lower knee, and he was carried off on a stretcher after being treated by medical staff on the pitch, with Ivan Rakitic replacing him.
Barca have since released a statement, saying: “The first team player Andres Iniesta has a partial injury to the lateral collateral ligament in his right knee.
“When he arrives in Barcelona the player will have more tests to find out the exact extent of the injury.”
The home fans joined the Barca faithful in applauding Iniesta from the pitch, with a number chanting his name as he was taken down the tunnel.