According to the CV of Oddie Braddell, the actor will be playing the role of Wendel Manderly. Alex Graves is cited as the director, indicating that Braddell will possibly begin in the role during episode four or five. In the novels, Wendel is a large and honorable knight who fights at the side of Robb Stark and travels with him in the North in A Storm of Swords.
Also appearing in season three will be Kelly Long, who played the role of Lord Walder Frey’s wife in a season one episode. Long is a regular stand-in for the series, and notes on an industry website that she’ll be returning to her onscreen role as Lady Frey in season 3.
An intriguing mention of season four popped up in reports about two other actresses appearing in season three. Sophie O’Brien, who played a prostitute in Littlefinger’s brothel in two episodes last year, states on her CastingNow webpage that she’ll be in the third episode of season three and that she has a “speaking part.” O’Brien tweeted (*NSFW* link) earlier this month she has a role in season four as well, along with Pixie Le Knot, a well-known contortionist. It looks like Pixie Le Knot will be in episode three too this year, based on the tweet.