Simon Cowell is still "very shaken" and in constant pain after being rushed to hospital on Friday.
The 58-year-old music mogul was stretchered out of his London home in a neck brace after fainting and falling down stairs, and though he has been discharged and is expected to return to work on The X Factor on Sunday evening, he has reportedly been warned by medics the lights and heat in the studio could trigger a relapse.
But Cowell will still defy doctors' advice to rest until next week in order to support his contestants on the show.
A source told The Sun newspaper: "Simon is suffering bad pains in his neck, and is still very shaken.
"He thought he may have broken his back, and he's told friends it was the most scared he's ever been in his life.