Zoe Ball will no longer present tonight's Comic Relief after a positive Covid test forced her to pull out.
She'll be replaced on the BBC One fundraising show by Alesha Dixon.
The Radio 2 presenter, 51, told fans she was gutted to "fall at the last hurdle" and have to miss the show following a positive lateral flow test this morning.
Britain's Got Talent judge Alesha will be stepping in to help raise funds for the cause instead.
Zoe wrote on Instagram : "Pook! fell at last hurdle and have had positive lat flows this am- noooooooo - gorgeous @aleshaofficial is going to work the double shift tonight on @ComicRelief, I owe you lady love.
"Good luck to Lenny, David, @mcguinness.paddy, @ajodudu, @vernonkay, and the @comicrelief gang, so many brilliant treats in store tonight."
But Zoe said she'll be watching from home instead to cheer everyone on.
She added: "I'll be watching & supporting from bed (probably in full make up, outfit, heels and all) might invite @joeldommett over #sickbay"
Comedian Joel Dommett joked: "NOOO! You already got the nails done!! Rest up.. you will feel fine in a couple of days! Xxx"
While a comment from the official Comic Relief account read: "Sending all our love to you Zoe, we love you"
And one of her fans pointed out: "Can’t believe that you ‘joked’ about catching it on air the other day! #jinx Get better very soon Zoe!"
Joel has also been forced to pull out of the show after catching coronavirus.
The Masked Singer presenter was set to host the charity event alongside Zoe, Lenny Henry, David Tennant, AJ Odudu, Paddy McGuinness and others.
He told fans earlier this week: "Super annoyed to report that I have the vid. This unfortunately means I have to pull out of hosting @comicrelief
"My incredible replacement is the better looking, more talented @vernonkay who is ace. I’ll be watching from home donating loads of money like everyone else!"
Comic Relief kicks off at 7pm on BBC One tonight and airs until 10pm.
It will include a special edition of The Repair Shop with Dawn French, Jennifer Saunders and Dame Judi Dench, a special sketch starring Kylie Minogue and the case of Ghosts, Jack Whitehall taking on mini golf and an adults-only bedtime story from Stephen Fry, Sue Perkins and others.
