The 27-year-old was said to be in the frame for a role on the talent show when Simon Cowell takes it to America next year.
However it has now been claimed Carey, 40, is in negotiations for a role on the show, which could ruin Cheryl's chances of bagging a judging spot.
A source told UK newspaper the Sunday Mirror: 'The Fox executives are totally against Cheryl joining the panel.
'They're saying that together with her accent being difficult to understand, and nobody knowing who she is, she doesn't have the star qualities to draw in an audience.'