Sunderland remain one of the most active teams in the transfer market this summer, showing they have not finished adding to their squad.
Paolo di Canio's latest signing the 10th of Sunderland's busy summer, is Ondrej Celustka.
Celustka is not a name the casual Premier League fan will be aware of, so what can we tell you about him?
Here are five facts...
1) Celustka is a 24-year-old right-back from the Czech Republic, who is a former under-21 international, who can also play at left-back.
2) He signs on loan from Trabzonspor for the season, for who he signed from Slavia Prague in 2011 for £800,000.
3) Celustka had played four Europa League matches already this summer, featuring for the Turks in the qualifiers against Derry City and Dinamo Minsk, winning both rounds.
4) He has Champions League experience, making his debut in a historic 1-0 away win over former champions Inter Milan in September 2011, in which he scored the winner.
5) He was a losing finalist in last season's Turkish Cup Final, seeing his side defeated 1-0 by Fenerbahce.
Check him out in action below...
Sunderland fans, will he be first choice?