Fresh off of Sunday’s rather anticlimactic season finale for AMC’s immensely popular drama series The Walking Dead, the network is making some casting shifts ahead of the upcoming fourth season.  Immediately after Sunday’s episode, word broke that David Morrissey—who plays the villainous The Governor—would return as a series regular for season four, and now Chad Coleman (Tyreese), Sonequa Martin-Green (Sasha), and Emily Kinney (Beth) have been upped to series regulars for the impending season.  Hit the jump for more.the-walking-dead-season-4-emily-kinneyNews of the casting shifts comes courtesy of THR, which adds that Melissa Ponizo (Karen) will return as a recurring guest star in season four.  Karen was the only remaining member of The Governor’s attack party after Morrissey’s character went full-psycho on his own group following the botched—and did I say anticlimactic?—showdown at “The Prison.”Tyreese and Sasha were introduced halfway through season three, but Beth has been a part of the show since Rick’s group came across “The Farm” in season two.  As a number of the show’s female characters perished this past season, it appears that Beth will be getting a bit more screentime next year.  Production on season four gets underway this summer in anticipation of a likely October premiere. Scott M. Gimple was recently installed as the series’ new showrunner, as he takes over for departing showrunner Glen Mazzara, who himself took over for original showrunner Frank Darabont halfway through season two.  Such is life behind-the-scenes on The Walking Dead.david-morrissey-the-walking-dead-season-4