The 60-year-old is allegedly unable to travel to the UK from his home in Los Angeles to film the special in October as he continues to recover from his back injury.
However, a source told The Sun that Ashley Banjo is expected to fill in for Simon during the non-competitive festive special. HELLO! has contacted representatives for Britain's Got Talent for comment.
The horrific accident has forced Simon to miss out on this year's live shows. Diversity star Ashley has stepped in for him on the judging panel.
WATCH: Everything you need to know about Simon Cowell's bike accident
Meanwhile, the festive one-off is set to feature some of the best acts that have appeared on the ITV show over the past 14 series. It's been tipped that the likes of Susan Boyle and Paul Potts are to be on the list of potential performers who could return.
Since last month, Simon has been keeping a low profile at his home in Los Angeles after injuring his back during the accident. The dad-of-one fell off his electric bike while out with his son Eric and partner Lauren Silverman, and underwent emergency surgery.
Simon has been keeping a low profile during his recovery
At the time, the X Factor judge reassured his fans that he was doing okay. "Some good advice… if you buy an electric trail bike, read the manual before you ride it for the first time," he tweeted. "I have broken part of my back. Thank you to everyone for your kind messages."
Prior to his accident, Simon opened up about his time in lockdown with Eric. He told Terri Seymour on Extra: "I was concerned how [Eric] was going to cope with all of this. He has been absolutely amazing… He is still able to do schoolwork, and now we are camping on the weekends in the garden."
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