Cheryl Cole and Gary Barlow were set to perform a duet together for the Children In Need charity, but it appears the former Girl's Aloud star may have to pull out.
The Take That star had been lining up an appearance with the singer at Children In Need Rocks in Manchester on Thursday.
It would have been Cheryl's first UK performance for months in a turbulent year which saw her axed as a judge from the US version of X Factor.
It's understood that organisers have been informed she's having problems with her throat.
Gary joked on Monday that he was now thinking of contingency plans for the event which he has put together.
Speaking at rehearsals in London, he said: "She's ill. We're waiting to hear.
"It's meant to be a surprise but that's the plan - if not, I don't know what we're going to do.
"I might just have to get on the piano and do a bit of Roll Out The Barrel."
So far there has been no comment from Cheryl's camp.
Photo: © Rex