According to EW, McDonough will recur as Quarles, a mobster from Detroit who comes to town with intentions of becoming a crimelord. Williamson plays Limehouse, a man who is desperate to protect his land.
Jeremy Davies will also return to the FX series. Season 3 premieres in January.
In other casting news ...
Janeane Garofalo is joining the cast of Adult Swim's 'Delocated.' Garofalo will play Susan Shapiro, the head of the TV network producing a reality show about Jon (played by series creator Jon Glaser). The series stars Glaser as a man in the witness protection program. Steve Cirbus, Jacob Kogan, Yung-I Chang and Ali Farahnakian also star. [Adult Swim]
The Rock is returning to 'Monday Night Raw.' Look for Dwayne Johnson to appear on the Nov. 14 episode. [WWE]
Rachael Harris will guest star on 'New Girl.' The 'Hangover' scene-stealer will play Tanya, a quirky vice principal at Jess' (Zooey Deschanel) school. Look for Tanya to party with Jess and her roommates in an episode airing later this season. [EW]
Anika Noni Rose is returning to 'The Good Wife.' The Tony-winning actress will return for one episode as Wendy Scott-Carr, Peter Florrick's opponent in the State's Attorney race. [TVLine]
Megan Stevenson and Wes Brown will guest star on 'Hart of Dixie.' Stevenson will play Zoe's friend from New York who visits Bluebell and Brown will play a love interest for Zoe, the town veterinarian. [Zap2It]