According to oliverpowell (who has already proved a solid source), the role of Jory Cassel—Winterfell’s captain of the guard—has gone to popular Scottish actor, Jamie Sives. Sives has a long list of credits, including appearances in genre productions such as Doctor Who, the new Clash of the Titans, and the historical adventure Valhalla Rising. In 2002, Sives garnered a number of film festival nominations and awards for his performance in the independet film, Wilbur (Wants to Kill Himself), which earned him attention from diverse sources such as the BBC.
Below is one of a number of videos featuring Sives available on Youtube: