The midfielder played for Arsenal for four seasons before leaving at the end of his contract to join Milan on a free transfer.
He again finds himself out of contract and is set to sign a deal with Arsenal according to numerous reports after spending the last two weeks training at the club.
Arsenal are hoping to rush through the transfer so that he will be free to play against Fulham this weekend.
Flamini, now 29, has won three caps for France but the last of those came back in 2008.
He played over 100 Premier League games for Arsenal and came off the bench for them in the 2006 Champions League final.