Helen Skelton stepped in to replace Steph McGovern on her Channel 4 chat show after the host had to self-isolate.
The Countryfile star, 37, explained that McGovern, 38, had tested negative for the virus but was taking time off her Packed Lunch programme in line with Government guidelines.
She told viewers: “Obviously, I am not Steph. She is fine but she’s having to self-isolate. She’s tested negative for coronavirus but she’s following Government guidelines and she will be back very soon. We miss you Steph, I hope I do you proud.”
Pointing to a nearby TV screen, Skelton quipped: “I’ll try not to break anything, but this is looking loose already.”
She did not reveal why McGovern had been required to self-isolate.
Watch: Steph McGovern Strictly Come Dancing
According to current advice, the self-isolation period for contacts of a positive coronavirus case is 10 days.
Skelton co-hosted Blue Peter from 2008 until 2013 and since 2014 has been a presenter on Countryfile.
Friday’s episode of Packed Lunch featured Strictly Come Dancing winner Bill Bailey and his professional partner Oti Mabuse, former home secretary Alan Johnson and actor Luke Kempner.
Former BBC Breakfast presenter McGovern launched her Channel 4 show from home last year during lockdown.
It had been due to debut from a studio in Leeds, but instead the presenter broadcast from her living room in Harrogate because of the coronavirus crisis.
McGovern eventually announced the home broadcast would be paused to “give my family our home back”, and the show later resumed in the studio as intended.
Watch: Strictly champ Oti Mabuse's got her fingers crossed for a safe UK tour