Hanno will face a disciplinary committee in London on Wednesday following his red card at Franklin's Gardens on Saturday.
Dirksen was sent off by match referee, Alexandre Ruiz (France), for an alleged dangerous tackle on the Northampton Saints replacement, Juan Pablo Estelles (No 23), in the 78th minute of the match in contravention of Law 10.4 (e).
Pamela Woodman (Scotland), Philippe Cavalieros (France) and Donal Courtney (Ireland) have been appointed as the independent Disciplinary Committee for the hearing which will take place in London tomorrow (Wednesday, 13 December).
Law 10.4 (e) Dangerous tackling of an opponent
Under World Rugby's Sanctions for Foul Play, Law 10.4 (e) carries the following sanction entry points - Low End: 2 weeks; Mid-Range: 6 weeks; Top End: 10 to 52 weeks.