Last year, Sharon made a return to the panel, alongside Louis Walsh and Nicole Scherzinger, with Simon Cowell reportedly keen to break recent tradition and keep the panel the same for next year’s series.
However, Sharon - who mentored 2016 runner-up Saara Aalto - has admitted this may not happen, should she require surgery for a back condition.
Speaking on US chat show ‘The Talk’, she told viewers: “I have a trapped nerve... and I had to have, what is it when you have a baby, an epidural. There was no baby, but I had an epidural and I woke up to no baby, just a bad back... That’s why I wasn’t in last week.
“I wait another week and if it hasn’t fixed it then I have to have surgery.”
‘The X Factor’ is renowned for its ever-changing panel of judges, which has never stayed the same for longer than three series in a row.
It looked like that could be about to change at the end of the last run, though, with an insider telling The Sun: “Sharon has really enjoyed the show this year and is desperate to go back.
“The panel worked well and she knows Simon would love to have the same line-up again.”
HuffPost UK has contacted a representative for Sharon for comment.
Sharon did say in December that her commitments to ‘The Talk’ could prevent her from signing up to the talent show again, explaining: “I’m signed to CBS and I’ve been with them for seven years with amazing women on ‘The Talk’ and it’s up to Simon to see if they’ll let me do it.
“My whole life is travel so if I hadn’t been here I would’ve been in South America with Ozzy so the travelling doesn’t bother me it’s that I had to keep going back each week for the show.”