Korean international midfielder Ki Sung-Yueng dealt a blow to Swansea on Monday as the Premier League side announced he would miss the start of the season due to a knee injury.

The 28-year-old -- who Swansea signed from Celtic for £6million ($7.8m, 6.9m euros) in 2012 -- is to remain in South Korea after undergoing an operation on the knee he injured in a recent 2018 World Cup qualifier against Qatar.

"He will remain in South Korea to continue his rehabilitation, before returning to Swansea after Paul Clement's squad return from their pre-season tour to America," read a statement on the club website.

The club's medical team have been out to South Korea to assess him following the operation.

Although no date has been set yet for his return to action, the injury is not expected to keep him out long-term.

Swansea, who preserved their Premier League status by the skin of their teeth last term, are hopeful of strengthening their midfield in the coming days with Spaniard Roque Mesa who plays for Las Palmas.