Referee Andre Marriner admitted to Arsenal that he made a mistake on Saturday by sending off Kieran Gibbs in the Gunners' 6-0 loss to Premier League leaders Chelsea at Stamford Bridge.
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Alex Oxlade-Chamberlain handled a ball in the box with Arsenal already trailing 2-0 in the 17th minute, but Marriner issued the red card to Gibbs, sending off the wrong player.
Marriner's admission was revealed in a statement released by the referee's board hours after the match.
"Andre is an experienced referee and is obviously disappointed that an error of mistaken identity was made in this case," the statement read.
"Incidents of mistaken identity are very rare and are often the result of a number of different technical factors.
"Whilst this was a difficult decision Andre is disappointed that he failed to identify the correct player.
"He expressed his disappointment to Arsenal when he was made aware of the issue."
Technology is only used in the Premier League to rule on disputed goals, but Chelsea manager Jose Mourinho called for referees to be allowed to base decisions on video replays.
"The sending off is a big ammunition for people like me that thinks that one little screen in front of the fourth official is a big help against these kinds of mistakes," Mourinho said.
The Football Association confirmed Arsenal can appeal Gibbs' automatic suspension.
Chelsea's Eden Hazard scored the resulting penalty to increase Chelsea's lead to 3-0, before Oscar added to Arsenal's woe with a goal before half-time.
Samuel Eto'o opened the scoring after just five minutes and Andre Schuerrle doubled their lead just two minutes later at Stamford Bridge.
Arsenal boss Arsene Wenger, who was overseeing his 1,000th match in charge of the Gunners, took off Alex Oxlade-Chamberlain at half-time and also Laurent Koscielny.
But it made little difference to his team's fortunes as further goals from Oscar and Mohamed Salah completed a 6-0 win for the Blues.