Wallace is primarily a left-sided midfielder but can operate as a left-back, a bit like Julio Arca some may say.
Varga, who left the Stadium Of Light 3 years ago, has returned and will be aiming to make a better hash of it this time. He is best remembered by fans for his Sunderland debut against Arsenal when the Black Cats won 1-0. He looked unbeatable, but from then on his performances went downhill and he only managed 33 appearances before leaving.