South Korea's Asian Cup hopes have suffered a blow after Premier League midfielder Ki Sung-yueng was ruled out of the tournament with a hamstring injury.

The 29-year-old Newcastle United man played less than an hour at the tournament before being taken off during South Korea's opening win over the Philippines in Dubai.

Ki's withdrawal was announced as South Korea, two-time winners of the tournament and the 2015 runners-up, prepare to take on Bahrain in the round of 16 on Tuesday.

The pull-out has prompted speculation that Ki may announce his international retirement, after clocking up more than 100 appearances since making his debut in 2008.