The actor will appear in one episode of Season 4 and would return if True Blood is renewed for a fifth season, which doesn't seem like something to worry about. The news was first reported by TVLine.
Foley will play Patrick, an old army buddy of Terry Bellefleur (Todd Lowe), who, if you recall, decided he still wanted to be a parent to Arlene's (Carrie Preston) baby, even if the evil late Rene (Michael Raymond-James) is actually the father.
Foley also plays Henry on Grey's Anatomy, which will begin shooting in July.
The fourth season of True Blood premieres Sunday at 9/8c on HBO