The Ivory Coast international saw red in the closing stages of Chelsea's 1-0 home defeat to Jose Mourinho's side earlier this month for an off-the-ball incident involving Thiago Motta.
"The player's existing period of probation, which began on 15 July 2009 and was originally intended to run for two years, has also been extended to 15 July 2013," European governing body UEFA said on its website.
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Drogba has courted controversy in each of Chelsea's last three exits from the competition.
The World Cup-bound Ivory Coast striker was ineligible for Chelsea's first four European games this season after being banned for six matches, two of them deferred, for his behaviour in last year's Champions League semi-final against Barcelona.
He was heard mouthing expletives on live television after the final whistle having hounded referee Tom Henning Ovrebo, who had waved away four penalty appeals from Guus Hiddink's outfit.
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A year earlier, Drogba was dismissed in the final against Manchester United in Moscow after hitting out at defender Nemanja Vidic during extra-time. Chelsea went on to lose on penalties.
He was also sent off in the Champions League against Barcelona in February 2005 during a 2-1 defeat at Camp Nou.
