The German goalkeeper was sent off just 18 minutes into the match at the Stade de France - and although Wenger's men took the lead, courtesy of a first-half Sol Campbell header, second-half goals from Samuel Eto'o and Juliano Belletti sealed the European Cup for the Catalan giants, leaving the north London outfit heartbroken.
Having a one-man disadvantage for 72 minutes of the most important match of his managerial career, Wenger admits, will always rank as his biggest disappointment.
“I would like to replay the Champions League Final with 11 men in 2006,” he told Arsenal player. “It will be the regret forever.
“It has happened to us again with Bayern [this season]. That game I would love to have seen what would have happened if we stayed 11 against 11 against Bayern. These were huge games with so much at stake and you feel you cannot play with all your cards."
Wenger has never managed to land his hands on the European Cup - and there will always be a question mark over where he ranks among the pantheon of greats until he does. However, at the age of 64, the French coach still has a few years to rectify that.
Arsenal fans: Will Wenger win a Champions League winners' medal before he retires? Have your say in the comments section below.