However, news of his temporary replacement sparked a strong reaction from fans on Monday – with many delighted that Kelly Clarkson will be his stand-in on Tuesday and Wednesday's live shows.
WATCH: Simon Cowell breaks his back testing out new electric bicycle
Sharing the news on her Instagram in a fake AGT memo, it read: "My friend, Simon Cowell, is doing better now but was in an accident and won't be able to make Tuesday and Wednesday's live shows for AGT.
"But no worries America, someone far wiser, cooler, and hotter is taking his seat! The unbelievably amazing Kelly Clarkson. You're welcome in advance."
Kelly's fans were delighted with the news, with one commenting: "Don’t tell him we said so, but we’d rather have you in his spot any day!" Another added: "Woo hoo! I love it, so sorry to hear about Simon. But you're always America's favorite Kelly."
Kelly Clarkson is also a judge on The Voice US
Simon was rushed to hospital on Saturday afternoon after falling off his bike and breaking his back. The X Factor star was at home with son Eric and partner Lauren Silverman while testing his new electric bike in the courtyard when the accident happened.
His spokesperson told TODAY: "Simon had a fall from his bike on Saturday afternoon whilst testing his new electric bike in the courtyard at his house in Malibu with his family. He hurt his back and was taken to the hospital. He's doing fine, he's under observation and is in the best possible hands."
Simon has since taken to Twitter himself to reassure his fans. He joked: "Some good advice... If you buy an electric trail bike, read the manual before you ride it for the first time. I have broken part of my back. Thank you to everyone for your kind messages."
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