Cowell broke his back on Saturday while testing his new electric bike in the courtyard of his Malibu, Calif. home. He was rushed to the hospital, where he underwent a five-hour surgery. He is expected to make a full recovery.

"Some good advice, if you buy an electric trail bike, read the manual before you ride it for the first time," Cowell tweeted late Sunday, before adding, "Thank you to everyone for your kind messages. And a massive thank you to all the nurses and doctors. Some of the nicest people I have ever met."

Cowell's injury the latest setback to befall Americas's Got Talent's current 15th season. After a months-long shutdown due to COVID-19, the summer smash resumed production in late June — albeit with a number of new safety precautions in place. AGT relocated from its lavish Hollywood auditorium venue to an outdoor setup in Simi Valley designed to resemble a drive-in movie theater, with Cowell, Mandel, Klum and Vergara now seated an appropriate distance from one another. Additionally, the number of Judge Cuts episodes was trimmed from four to just one.