The Gunners insisted on a clause in the Spaniard's contract allowing them to buy him back if he ever leaves Barcelona, and the midfield ace has refused to rule out the possibility of an emotional return to north London.
He told talkSPORT: "It's absolutely fine by me [that the clause was inserted into the contract]. I enjoyed my time in Arsenal. I had some great years there. I developed as a player and as a person. I finished there as captain of the club and I will still follow the club and their results.
"I don't know if it's realistic that I would return one day. But maybe I said the same when I left Barca, so you never know. If that was the final thing Arsenal needed to agree on to let me go, then I'm satisfied."