Prior to the duo entering the camp, they addressed that Nella was missing from the line-up, and that she was exempt from the trial.
Dec said: "Now, unfortunately Nella is being seen by the medic, so she'll be back later, but it means she's now exempt from this trial. So let's go in there and see who will be doing it."
A spokesperson for ITV confirmed that Nella is being treated by the medics and told The Mirror: "For medical reasons, Nella Rose is being treated by the show's on-site medics and will be returning to camp shortly. As a result, she is exempt from the next trial."
The presenters then revealed that campmates Nick Pickard and Nigel Farage would be taking on the underwater challenge, Trial in Too Deep.
This comes after Grace Dent left the show citing medical reasons.
ITV said in a statement on Monday 27th November: "Unfortunately, Grace Dent has left the show on medical grounds. She has been a great campmate and will be missed by her fellow celebrities and viewers alike."
- Made in Chelsea spoilers: Maeva doubles down on disinviting Sam to wedding
- What happened on I'm a Celebrity 2023 last night? Episode recap
During the show, a message from Grace was read out to the camp, which said: "My dear campmates, I'm so sorry to let you down. I have left the camp for medical reasons. My heart is broken, I have loved and enjoyed getting to know you all.
"You've held me up and it's been a pleasure being your friend through this experience. Leaving you all at this stage will be one of the saddest things in my life. I love you all. Your friend, Miss Grace Dent."
I'm a Celebrity... Get Me Out of Here! airs at 9pm on ITV1 and ITVX.