#INSERT type:image caption:Hong Myung-bo's squad has some injury concerns heading into the World CupEND#
Kim Jin-su has been ruled out of South Korea's World Cup squad due to an ankle injury.
The Korean Football Association announced on Thursday that Park Joo-ho will replace the 21-year-old Kim, a highly-rated Japan-based left back, in the 23-man squad.
The 27-year-old Park, having recovered from a foot injury, is coming off a successful season in Germany with FSV Mainz 05.
QPR's Yun Suk-young played 90 minutes at left back in Wednesday's disappointing 1-0 home defeat by Tunisia.
The South Koreans, semifinalists at the 2002 World Cup, also have injury concerns over defender Hong Jeong-ho, who hurt an ankle in the loss to Tunisia.
South Korea will stage a training camp in Florida before heading to Brazil, where it kicks off its ninth World Cup campaign on June 17 against Russia.