At the time this looked very possible but after a couple of brilliant seasons,it became clear that Gael would never become a world class left back. In the last couple of seasons, he has been prone to the odd major error. He has been an excellent servant for the Arsenal,and it will be a sad day for the club when he leaves. It is very likely however,as the Frenchman only has one year left on his contract. Gael has expressed his desire to leave and Arsene is looking to cash in this Summer rather than see another Frenchman leave on a free transfer, like Flamini.
My personal choice to fill the left back spot would be Leighton Baines of Everton. I believe he has been the best left back in the country over the past couple of years. He is an excellent defender, and would offer a great option for set pieces. Instead of Van Persie constantly blasting the ball over the bar. He is however going to be considerably more expensive and if Man City are interested then there is no way we could match the transfer and contract offer they would put on the table.
Another far cheaper option would be to move Thomas Vermaelen to left back. He played there for Ajax and still does for Belgium. He would clearly do a very good job at left back, but I can only see this happening if we sign both Samba and Cahill which is looking unlikely. Therefore Enrique is the most likely and sensible option and I believe it is very likely we will see him lining up alongside Vermaelen and co next season at the Emirates Stadium.