The celebrity cook is due to appear alongside long-time MKR judge Manu Feildel after Pete Evans was dumped from the cooking competition.
While promos for the show have featured Nigella as a prominent part of the show, The Australian reports she will only appear in half the episodes.
The publication said she "will appear only for the first round of the show" before former MasterChef judge Matt Preston takes over her duties, with Colin Fassnidge and Curtis Stone reportedly judging the finals.
Fans were baffled by the news Nigella would not be appearing in every episode of the competition.
"Don’t see any of that in the on-air promos!" a TV writer said on Twitter.
"That will be weird," another replied.
"If true the on-air promos are a bit of a con," the TV writer added.
Another said on Twitter if Nigella was only in half the episodes they would only be watching half the season.
Channel Seven released the first teaser for MKR in June, which opens with Nigella wearing a red dress in the back of a luxury car.
Following the promo, fans took to social media to share their excitement about Nigella's involvement.
"Nigella and Manu, can't wait for the show to begin to see the chemistry between them,” one shared, while someone else said, “Yesssss! Two of my faves! So excited”.
“Could almost be worth watching again now! Hope it really is going back to its roots, the early seasons were brilliant,” a different user remarked.
After a year off-air, MKR hopes to make a triumphant return in 2022 with its new hosting lineup and a slightly altered format.
"It's state versus state as the beloved competition goes back to its original recipe – real people cooking real food, in their own homes, serving love on a plate to the judges and their fellow contestants," Seven said in a statement.
Yahoo Lifestyle has contacted Channel Seven for comment.
My Kitchen Rules premieres on Sunday August 7 at 7pm on Channel Seven.
Never miss a thing. Sign up to Yahoo Lifestyle’s daily newsletter.
Or if you have a story idea, email us at firstname.lastname@example.org.