The 19-year-old, who arrived at Upton Park from Manchester United on deadline day of the January transfer window, is accused of using homophobic language on the social networking site when responding to another user.

Morrison told the FA his outburst was prompted by racist abuse from individuals he classified as United fans disgruntled at his decision to leave the club, but it now appears this explanation has not been considered sufficient to avoid a charge.

He has until 4pm(GMT) on February 17 to respond to the charge.