B1A4's CNU will be receiving surgery for an injury to his knee.

In an article by TV Report it was revealed that CNU (Shin Dong Woo) has been suffering from damage to his knee cartilage since August. The injury was reportedly sustained prior to B1A4's most recent comeback "Sweet Girl."

However, because it had been over a year since B1A4's last comeback, CNU decided to push forward with his group's promotional schedule as to not disappoint his fans. As a result, CNU carried out all of B1A4's performances and practices while receiving regular, outpatient treatment. Now he needs urgent surgery to take care of his injury.

On September 4, officials from B1A4's agency WM Entertainment confirmed the injury and need for surgery in another article with Daily Sports.

"B1A4 will host concerts on September 12 and 13 and we will make sure that it will not be hard on his knee," the company said. "We are planning for surgery after the concerts." Despite the promise, though, fans are incredibly concerned about the singer's health.

B1A4 released "Sweet Girl" on August 9. The song has heard a lot of praise for how well it showcases the musical talent of each B1A4 member. As part of their comeback celebration the group will host their two upcoming concerts at Yonsei University.

We hope CNU recovers quickly!