Dermot O’Leary made the announcement just moments into the show and sent well wishes to his “boss”, but then implied that the fall may have been down to his fellow judges.
Simon was rushed to hospital after fainting at his London home and falling down the stairs “while on his way to heat up milk for son Eric”.
Dermot explained: “There they are, our X Factor judges. Now, you might have spotted one judge is missing. That’s because, as you may have heard, Simon was taken to hospital yesterday.
“But he’s doing fine. He’s back home now watching the show – or possibly Autumnwatch – who knows? He loves a badger. But we do want to say get well soon boss and hope to see you fighting fit very soon.”
Dermot then hinted that Simon’s fellow judges Nicole Scherzinger, Louis Walsh and Sharon Osbourne were behind his fall.
He said: “Oh you’re loving it you three! So, fess up, the question the whole country wants an answer to: Who put the banana skin at the top of the stairs?”
Louis gasped: “No, Dermot, I was boiling the milk. I was boiling the milk downstairs. They were upstairs, so it was one of these two.”
Dermot then noted: “It’s like murder on the Orient Express. You all had your motives!” as Nicole confessed: “It was a team effort. We both did it.”
Louis then hinted that Sharon was hiding the truth, nudging his co-judge and shouting: “Sharon, come on!”
Sharon replied: “No, I was in the library with a candle,” as Nicole added: “I was with the bananas, I guess.”
Cheryl later made an appearance and sent a heartfelt message to Simon while looking into the camera, saying: “First of all, I really miss you Simon. I know you’ll be watching at home. You’re very, very missed and we love you.”
Express.co.uk has contacted a representative of Simon Cowell for comment.
The X Factor continues tomorrow on ITV at 7pm.