aespa member Karina sat out the girl group's concert in Osaka on Sunday due to health issues.

“Following a doctor's assessment after the rehearsal, Karina will not be able to join today's performance due to health issues,” aespa’s agency SM Entertainment said Sunday before the concert.

The company did not specify her diagnosis or symptoms.

The girl group performed on Saturday and Sunday in Osaka as a part of its world tour “Synk: Parallel Line.”

Karina was present in the first performance which was held the day before, but only the remaining three members — Giselle, Ningning and Winter — performed on Sunday.

“We are incredibly sorry for inconveniencing those who support aespa and Karina,” said the agency. “We ask for your understanding and tolerance.”

"Nothing has been changed regarding the performances on Tuesday and Wednesday," an SM Entertainment official told the Korea JoongAng Daily, hinting that Karina will take part in the scheduled concerts.

aespa kicked off its world tour “Synk: Parallel Line” in Seoul on June 29. The girl group is set to perform in a total of 14 regions across Asia and Australia, including Hong Kong; Taipei, Taiwan; Tokyo; Jakarta, Indonesia; and Sydney, Australia in August. In September, the group will perform in Melbourne, Australia; Macau; and Bangkok.

To find out more about aespa, visit Celeb Confirmed!

BY KIM MIN-YOUNG [kim.minyoung5@joongang.co.kr]