Another actor has been cast for a new role in the upcoming fourth season of Game of Thrones.

Michiel Huisman, known for his roles in Nashville and Treme, will be playing a character introduced in season 4, according to a Wednesday report by The Hollywood Reporter. Producers are keeping the identity of his character a secret. N

News of his involvement in the popular fantasy series was made known after he posted an Instagram photo of himself exercising with a caption revealing that he was preparing for the show.

Another new addition to the show, whose role is being kept under wraps as well, is Mark Gatiss (Sherlock, Doctor Who). Entertainment Weekly reported the news about Gatiss in late July but his role on the series is still unknown.

Enstars recently reported that Joseph Gatt had been cast on the series but his role has not been confirmed, despite IMDB's claims that he'll be playing Styr, the hairless leader of a group of wildlings.

As for the new actors whose roles have been confirmed, Roger Ashton-Griffiths will be playing Mace Tyrell, father of Margaery (Natalie Dormer) and Loras (Finn Jones). Pedro Pascal has been cast as Prince Oberyn Martell, otherwise known as The Red Viper. This character will be an important part of the new season. Finally, actress Indira Varma was cast as The Red Viper's love interest, Ellaria Sand.

Season 4 of Game of Thrones will premiere in Spring 2014, though a specific premiere date has not yet been announced.

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