Where was Chansung during 2PM's special performance on Inkigayo?

Boy band 2PM put up a terrific performance of Without U on yesterday's Inkigayo, despite the fact that they only had five members performing. However, many noticed that member Chansung was missing from their special World Cup stage, which was confusing, as he was there for the previous performance of Without U. Although it's still unclear what specifically happened to the maknae, it's now believed that Chansung was injured or is currently ill. 2PM won the Mutizen for that week, and while the members were thanking fans, Junho said,�"Junsu and Chansung, we hope you two recover soon!" http://www.youtube.com/watch?v=c-h9uZQl92w The group must be suffering a lot lately,�both mentally and�physically. Lets hope this doesn't lead to performances with only four members.