The 'Call My Name' singer, who fell out with Cowell after snubbing his offer to rejoin the show following her axing from The X Factor USA last year, assisted Gary Barlow at Judges' Houses this weekend.
According to The Sun, Cole made it clear, after her former boss welcomed her back to The X Factor on Twitter, that her long-awaited return was done as a favour to Barlow.
"I saw Simon's tweet. I'm not doing this for him," she is quoted as saying. "I am doing this for Gary as he's my friend and he asked me to do it."
After filming of Judges' Houses wrapped, Barlow wrote on Twitter: "Thank you @CherylCole for all your help this weekend. The contestants and I loved having you there xx."
Copyright: Ken McKay/Rex FeaturesIt has also been claimed that Robbie Williams will give a 'master class' to Barlow's team during the live stages of The X Factor after being dropped for Cole as his Take That colleague's guest judge.
"Robbie will still have a role to play and an important one at that," a source said. "Gary hasn't snubbed him, quite the opposite."
New extracts from Cowell's unofficial biography have revealed the 52-year-old's desperation to also get Dannii Minogue back on The X Factor this series.