A new man will be threatening Nucky Thompson’s reign on the upcoming third season of HBO’s Boardwalk Empire. Bobby Cannavale has joined the cast of the mob drama as a series regular. He will play Gyp Rosetti, a charming but ruthless gangster who challenges Nucky (Steve Buscemi). The cast of Boardwalk Empire, created by Terence Winter and executive produced by Winter, Martin Scorsese, Tim Van Patten, Mark Wahlberg and Stephen Levinson, is a regular short following the demise of Michael Pitt’s character in the second season finale. The series repeated as a double SAG Award winner this past weekend in the best drama ensemble and best actor (Buscemi) categories. Cannavale, Emmy-winner for his recurring role on Will & Grace, recently completed a ten-episode arc on Nurse Jackie and wrapped production on the feature Lovelace. The actor, repped by ICM and Framework, starred alongside Chris Rock on Broadway last year in The Motherf**er With The Hat.