5. Cesc Fabregas
Spanish midfielder Fabregas is undeniably one of the greatest players to have graced Arsenal in recent seasons. The 26-year-old captained the Gunners and made over 200 appearances under Arsene Wenger during an eight-year stint in the first-team setup.
With Arsenal's trophy drought showing no signs of coming to an end, he agreed to move back to boyhood club Barcelona in August 2011.
In the immediate aftermath of Fabregas' departure, Wenger obviously found it nigh-on impossible to adequately replace his significant and consistently excellent contributions.