Alison, 46, and Dermot, 48, usually host the show every Friday.
But last week they filled in every day while Holly and Phil took a break from work.
Alison and Dermot on This Morning
An insider told The Sun: “There are no firm plans to replace the hosts but producers always keep an eye on potential heirs.
“Alison and Dermot will have been scrutinised during their week-long stint to see how This Morning would look if they took over full-time.”
And the verdict was very favourable.
The source added: “They are very much viewed as a breath of fresh air and have had a largely positive response from viewers.”
What do viewers think of the Alison and Dermot?
Viewers hailed their presenting a success.
One said: “Alison and Dermot I’m already OBSESSED, I love this so much.”
Meanwhile, another fan wrote: “Loving Alison and Dermot on This Morning already, so refreshing!”
When she landed the Friday show with Dermot, Alison said: “I never dreamt that when I first joined This Morning, initially for a few months, that I would still be there 19 years later.
“I genuinely care about the show and the viewers who watch, so it’s a huge privilege and honour to be hosting a show I adore so much.
“I’m just really excited to be doing even more of what I love alongside the lovely Dermot.”
Dermot spoke about their working relationship earlier this month.
He said: “Getting to know her and getting to trust her – our friendship is definitely the highlight.
“It’s lovely how it’s been nurtured over time.”
He added: “I’ve found a sister and a friend, which is nice. Something has really clicked in the last four months.”
ITV declined to comment on this story.