Little Mix star Jesy Nelson was secretly nursing an injured knee while performing at London's Apple Music Festival on Tuesday (22Sep15).
The Black Magic hitmakers served as the opening act for One Direction during an intimate gig at the Roundhouse venue, but unknown to their fans, Nelson hurt her knee before taking to the stage.
It wasn't until Wednesday (23Sep15) that her injury was revealed, when her bandmate Jade Thirlwall took to Instagram.com to post a photo of Nelson's bandaged knee.
She wrote, "Last night poor Jesy had a leg injury and STILL performed like a pro!"
Nelson has yet to reveal what happened to cause the injury.