"Game of Thrones" may have added another actor to its cast line-up of season 4. Michiel Huisman has reportedly landed a recurring role on the HBO medieval series, but what character he will play remains a mystery as of press time, AceShowbiz said.

Report of Huisman's casting on "Thrones" first surfaced after his trainer posted a photo of him working out for the role. Fitness trainer Aaron Williamson wrote, "1 more week w/ Michiel Huisman getting him ready to kick ass on Game of Thrones. Proud of this guy's dedictation; huge transformation from his Treme days."

The Dutch actor plays Sonny, a drug-addicted musician, on HBO's "Treme", which will air its five-episode final season in December. Also appearing in movies such as "The Young Victoria " and "World War Z", the 32-year-old currently stars as Liam McGuinnis, a love interest for Connie Britton's Rayna, on "Nashville".

"Game of Thrones" season 4 will be based on the second half of George R. R. Martin's "A Storm of Swords". Production for the new installment began earlier this summer for a 2014 premiere. The show has earlier cast Chilean actor Pedro Pascal as Prince Oberyn Martell a.k.a.Red Viper, Indira Varma as Red Viper's love interest, and Mark Gatiss in a secret role.