Arsene Wenger has admitted that he regrets selling Ashley Cole to Chelsea in 2006.
Boyhood Arsenal fan Cole came through the youth ranks at the club and went onto win four major honours (two FA Cups and two Premier League titles) under Wenger's tutelage. He was a big part of the famous Invincibles side of 2003/04, and looked destined for great things in north London.
However, a disagreement over a new contract in 2006 led to a breakdown in relationship between club and player. Then in one of the most controversial transfers in Premier League history, Cole switched north London for West London as William Gallas went the other way, along with a fee of £5million.