We take a look back on new addition's career so far.
Sunderland signed South Korean midfielder Ki Sung-Yueng in the run-up to transfer deadline day.
The stylish ball-player began his professional career in his homeland with FC Seoul before moving to SPL giants Celtic in August 2009.
He enjoyed a successful spell at Parkhead, making 66 league appearances and winning both the Scottish Cup and SPL title.
The Barclays Premier League came calling in summer 2012 as Ki joined Swansea, making his league debut against Sunderland in a 2-2 draw.
He was a regular for the Swans last season, picking up a Capital One Cup winner's medal as the Welsh club beat Bradford City in the final.