The Take That star will perform a duet with his last remaining act on Saturday, December 8, should Maloney make it past the semi-finals.
Producers are said to have struggled to secure a leading pop act to duet with Maloney, following the likes of Rihanna, Robbie Williams and Beyoncé in the past.
"Christopher has never been in the bottom two before and bosses are working on the likelihood that he will be in the final - and this has caused a real headache for them," a source told The Sun.
"In the past, the acts who have reached the final have had some sort of star quality or credibility which has attracted big-name talent wanting to perform with them.
"But unfortunately that is just not the case with Christopher. He has got a good voice - but it is fair to say he is probably the uncoolest singer to have ever got this far.
"So producers have lined up Gary to sing with him instead. Of course Gary is a massive star, with hits including 'Could It Be Magic', and Christopher will still be thrilled to sing with his mentor."
Last year, the three remaining acts sang with their mentors Gary Barlow, Tulisa Contostavlos and Kelly Rowland.
However, X Factor producers are said to be hoping to line up other big stars to duet with the finalists this year.
Jane McDonald had previously spoken of her interest in performing with Christopher Maloney in the live final.
Photo gallery: 'The X Factor' quarter-final results show: