Lucy was absent from last weekend's episodes after coming down with the flu and now her friend and fellow contestant, Rylan Clark, has told The Sun: "Her health comes first and the show comes second at the moment."
The singer/songwriter, who gained the public's votes by performing her own songs on the show, has reportedly failed to attend any practice sessions this week.
If Lucy, who is one of Tulisa's acts, does return to the show this weekend she is due to perform a version of Rihanna’s No 1 hit 'Umbrella'.
Earlier this week, a source told The Daily Mirror Lucy is furious with show bosses for trying to get her to sing cover versions.
And the source told the paper the singer also wants to “be paid for the songs which she wrote that are selling on iTunes”.
Jade Ellis, Tulisa Contastavlos and Ella Henderson with Lucy Spraggan at the Skyfall premiere on Tuesday
However, a show spokeswoman insisted Lucy would be back: “She is very happy show-wise.”
And Rylan has rubbished the rumours that Lucy is unhappy with the show's process. He told The Metro: "To be fair, I think that’s just hearsay. We have a major creative input in what we sing and what we don’t sing."
He also confirmed that his fellow hopeful "is genuinely really, really ill at the moment," but is hopeful that she will take part in the live shows this weekend.
Last week axed 'X Factor' duo MK1 branded the guitar-strumming favourite a grump.
In an interview with Radio 1Xtra, rapper Simeon said: "Lucy Spraggan had so many bad days and it was hard to try to connect and talk to her."
Charlie added: "She sounded a bit grumpy. Don't get me wrong, she's talented. But a smile wouldn't go amiss, if you know what I'm saying."