However, Cowell fans are not to be disappointed as this is only a temporary change and the 60-year-old show judge will be back soon after reporting good recovery.
The show kicked off Tuesday night and the 38-year-old The Voice judge graced Cowell’s seat and was quick to adapt to the style and was even seen getting along with the other judges on the bench.
However, it was evident that everyone on the show was missing Cowell.
“Obviously we miss the boss. There is no one who could actually take his place, even though Kelly did absolutely amazing today,” judge Heidi Klum said. “She did an amazing job and she had so much fun, but no one is like Simon. That is just the way it is.”
Sofia Vergara was also missing Cowell on the show and was really looking forward to having the London native back.
“I want Simon back. This is my first time. I want things to be normal,” the 48-year-old said.
Co-judge Howie Mandel also agreed to what Klum had to say about Cowell, and added that he was “irreplaceable”.
“We have been told he has been recovering tremendously,” Mandel, 64, told Entertainment Tonight in an interview “I would not count him out before the end of this season.”
"The latest I've heard is that after a six hour operation, and some fused discs, and the rod put in his back, yesterday, he was up on his feet, already, he's already mobile! So, as I've been saying to a few other people, I wouldn't count out seeing Simon again before this season's end,” he added.
The former Deal or No Deal host had more updates on the producer’s conditions on the show.
“He’s had a six-hour operation and he is already on his feet, which is above and beyond expectation, so I am thrilled,” he said. “I love the guy, I miss the guy, and my hearts and minds are with him and each and every moment.”
Mandel also told E! News that the crew was “a little bit in disarray” because of the worry around Cowell and “didn’t know what to expect”.
A spokesperson had confirmed on Saturday that Cowell fell while testing a new electric bike in his Malibu house courtyard.
"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 broken his back,” the statement said.