 When Rob Lowe (I) (qv) announced he would be leaving the show in  the fourth season, among the names considered to replace him were  Dermot Mulroney (qv), Judd Nelson (qv), Macaulay Culkin (qv)  and Jon Cryer (qv). The job eventually went to  Joshua Malina (qv), a longtime friend of Aaron Sorkin (qv) who  has been in everything Sorkin has written since he appeared as a  member of the ensemble in Sorkins play "A Few Good Men."