The media mogul said that Tulisa Contostavlos, Kelly Rowland, Louis Walsh and Gary Barlow were by no means safe following the relative disappointment of last year's show, identifying the Take That star as the one most likely to exit.
"I always thought that with Gary he would have the Take That commitment in 2012," Cowell told The Sun. "But there has to be a certain amount of unpredictability with this show, it is what keeps people interested.
"I don't know if I will keep the panel the same yet. No-one knows yet because I haven't decided."
Referring to Walsh's temporary axing from the panel in 2007 in favour of Brian Friedman, he added: "Look what happened last time I tried to fire Louis! But I wouldn't say he is safe. We have got to look at everything - the whole show and panel."
Cowell also suggested that the panelists struggled to cope with the "relentless" nature of the show, saying: "They felt it big time."
Barlow previously hinted that he would leave The X Factor to spend time with his family, while Rowland's team recently denied rumours of her departure.
> Louis Walsh on 'X Factor' return: 'I'm 50/50, I want my life back'
Watch Simon Cowell and the stars of Britain's Got Talent talking to Digital Spy below: