The FA on Friday charged the striker with violent conduct and he could face a three-match ban if he is found guilty.
Referee Keith Stroud told the FA he had booked Drogba for going towards the opposing fans but did not see him throw the coin into the crowd.
"Although Didier Drogba was hit by an object, that does not excuse his subsequent actions. He also recognises that, has not sought to justify it that way, has sincerely expressed his regret and has apologised for the incident.
"The matter will be dealt with internally by the club after the FA and police processes are completed."