Winger Mavrias joins up.
Sunderland AFC have confirmed the signing of Greek international Charalampos (Charis) Mavrias from Panathinaikos for an undisclosed fee.
Mavrias, 19, arrives on Wearside after agreeing a four-year deal with the Black Cats.
The Greek midfielder came through the Athens side’s academy. He made his club debut in the UEFA Champions League as a 16-year-old in 2010, becoming the second-youngest player ever to play in the competition.
The youngster made 59 domestic and 11 European appearances for the Greek side, scoring six goals.
He has also made two appearances for the Greek national side, as well as being capped at U17, U19 and U21 level.
Mavrias has been assigned the squad number 35.