Sunderland have completed the signing of defender Ondrej Celustka on season-long loan from Turkish club Trabzonspor, the Premier League side confirmed on Monday.
Celustka, 24, made appearances for Trabzonspor following spells at FC Tescoma Zlin, Slavia Prague and Palermo. He also played in 18 games for the Czech Republic Under-21 national side.
Celustka arrives at the Stadium of Light just five days prior to the start of the Premier League season and is Sunderland manager Paolo Di Canio's 10th summer signing.
Di Canio has already brought in defenders Valentin Roberge and Modibo Diakite, goalkeeper Vito Mannone, midfielders Cabral, Emanuele Giaccherini, David Moberg Karlsson and El-Hadji Ba, plus strikers Duncan Watmore and Jozy Altidore.
The Black Cats will open their 2013-14 Premier League season on Aug. 17 at home to Fulham.