Former Arsenal boss Arsene Wenger admits the club made a 'mistake' in allowing Ashley Cole to leave the club for Chelsea in 2006.
The Gunners lost their academy product to Jose Mourinho's then Premier League champions in exchange for £5million and French centre-back William Gallas.
In his 2006 autobiography My Defence, Cole wrote that he nearly crashed his car and was 'trembling with anger' when he discovered the Gunners were only willing to pay him £55,000 per week.
But he went on to win four FA Cups, the Premier League and the Champions League at Stamford Bridge, while the Gunners continued to lose big-name stars such as Thierry Henry and Cesc Fabregas within the next five years.