The Gunners agreed a deal to sign Toure, who at the time was plying his trade with Belgian side Beveren, in 2003 after he impressed on trial.
However following a delay in gaining a work permit for a move to join his brother Kolo at the Gunners, the Ivory Coast international opted for Ukrainian outfit Metalurh Donetsk.
Toure has since established himself as one of the finest midfielders in the game during his time with Spanish giants Barcelona and now City.
When asked where he puts his failure to sign Toure in his list of regrets, Wenger simply responded: "At the top."
The Frenchman added: "But let's not forget Toure had an agreement with Arsenal. We waited for his passport in Belgium but he went to Ukraine [instead].
Arsenal boss Arsene Wenger reveals failed attempt to sign Man City's Yaya Toure
Daily Star | Mar 29