South Korea's injury woes have gotten worse ahead of the 2018 FIFA World Cup as they lost a veteran midfielder in his club action.

Suwon Samsung Bluewings confirmed Thursday that their captain Yeom Ki-hun sustained a fractured rib during the first leg of their Asian Football Confederation Champions League round of 16 match against Ulsan Hyundai on Wednesday. The 35-year-old was brought down in a tackle by Ulsan's Richard Windbichler in the 76th minute and was later taken off the pitch on a stretcher. The video replay showed that Yeom's right rib collided with Windbichler's knee while landing.

Suwon said Yeom was transferred to a hospital in Ulsan, and a medical examination showed that he fractured the right fourth rib, which will make the player unavailable to play for at least four weeks.

Yeom, who represented South Korea at the 2010 World Cup, has five goals in 57 international matches. Although he wasn't considered as a starting member for the men's national team, the all-time assist leader in the K League 1 had been tapped as a promising backup member who could help South Korea at the upcoming World Cup in Russia.

Yeom's injury will give more concerns to South Korean head coach Shin Tae-yong, who is set to announce his World Cup squad next Monday.

Shin's side has already lost two key defenders -- Kim Min-jae and Kim Jin-su -- due to injuries. Both players are currently in rehabilitation, but it is still uncertain whether they can recover their best form with the World Cup only 35 days away.

Shin said last week that injured players and those showing a lack of form had been a headache for him ahead of the World Cup selections.

South Korea are in Group F with Germany, Sweden and Mexico at the 2018 World Cup. Shin's team is scheduled to assemble the World Cup members on May 21 and will play two friendly matches at home before flying to a pre-World Cup training camp in Austria. (Yonhap)