In the book, Peeta has two older brothers. According to a tweet by @ImDannyWilliams, his student and friend,, Isaac King will be playing Peeta’s brother in The Hunger Games: Catching Fire.
Here’s a photo of Isaac from his website:
He kinda resembles our Peeta! What do you guys think?
*Please note that we consider this as a rumor for now. It’s official when the information is from Lionsgate. 
