FX's Sons of Anarchy will be adding on to its already impressive guest star list, as it will reportedly be bringing on two new cast members for its upcoming sixth season.

According to TV Fanatic, Southland's C. Thomas Howell and Shameless' Steve Howey will both be coming on board the TV series to take on two crucial roles.

Howell will be playing an ATF agent whose motives are considered questionable while Howey will don the role of a Las Vegas motorcycle rider that runs into SAMCRO.

The two notable actors will join a Sons of Anarchy guest star list that includes the likes of CCH Pounder, Kim Dickens and Bridget Regan.  Ponder will portray a district attorney, Dickens will act as a Madame, and Reagan will more than likely play a call girl.

Sons of Anarchy is set to premiere its sixth season on Wednesday, Sept. 11 at 10/9 p.m. Central on the FX network.   Be sure to keep checking back for more of the latest details on the gritty biker TV series.

A recent SoA sit down interview that was participated in by a majority of the SoA cast at the Paley Center in N.Y. can be watched below.

Tags: Sons Of Anarchy television fx