Stadium of Light club continue overhaul.
Sunderland have signed Chunnam Dragons forward Ji Dong-Won for £3.1million to carry on their summer spending spree.
The 20-year-old has impressed during his short career and was runner-up for the K-League rookie of the year in 2010 after scoring eight goals in 26 games.
His form has attracted the interest of Newcastle United, and Dutch team PSV Eindhoven but the Black Cats have won the race.
The South Korean international is currently with his country’s squad in Jordan for the second qualifying for next year’s Olympics and he will fly to England immediately after Thursday’s match.
Ji will be the eighth South Korean to join the Premier League and the youngest so far. Manchester United’s Park Ji-Sung and Lee Chung-Yong of Bolton Wanderers were the only Koreans still playing in England last season.
The K-League side said the two teams had agreed in principle on the transfer and the forward was expected to sign a three-year contract later this month after a medical.
“I had the impression that Sunderland really wanted me,” Ji told Yonhap.
“I know there will be stiff competition for playing time, and my goal is to become the player that the team wants me to be in six months.
“I am also looking forward to playing against Ji-Sung and Chung-Yong, whom I both admire.”