Coogan says he is producing the currently unnamed comedy for an unknown broadcaster "and Rob's going to star in it".
"I love Rob. But I like him most when he plays a character. He does that a little bit doesn't he in Gavin & Stacey? He's mostly known as a personality who presents shows now ... But he is a fantastic character actor and we've not seen enough of that and I want to do that with him."
Coogan and Brydon have been regular collaborators on projects with director Michael Winterbottom, most notably in four series of mockumentary The Trip (pictured) for the BBC and Sky and the films A Cock And Bull Story and 24 Hour Party People.
Coogan was instrumental in delivering Brydon his big television break, associate producing the Welshman's breakout mockumentary series Marion And Geoff on BBC Two from 2000-2003 through Baby Cow Productions, the company he founded with Henry Normal and continues to deliver his own projects through.
However, the last time the pair appeared on screen together in a conventional sitcom was the 2002 I'm Alan Partridge episode Alan Wide Shut, in which Brydon played a member of Lyn's Baptist church whom Alan tells to "fuck off!"
Notwithstanding that he postponed shows in Cardiff and Bournemouth over the weekend due to laryngitis, Coogan is currently touring the live Alan Partridge show Stratagem around the UK. And in promotional interviews, he has teased the possibility of The Trip returning, with he and Brydon potentially venturing to the lands of their forefathers, Ireland and Wales.
The restaurant dining mockumentary, in which the pair play versions of themselves and indulge their love of celebrity impressions ran for two series on BBC Two between 2010 and 2014, then subsequently two more on Sky Atlantic and Sky One, most recently The Trip To Greece in 2020.
And Coogan reiterated to Radcliffe during their interview, broadcast on Saturday but recorded the week before, that "I never say never" to The Trip returning. "It was a strange discovery that, tap into versions of ourselves and be cantankerous.
He added: "The first series we were anxious. But then I turned up at the second and third one, Italy, Spain and Greece ... you can relax into it. You turn up, someone curates where you go, you eat fantastic food, there's always an amazing view. And all you have to do is talk rubbish."
Coogan has recently starred alongside Sarah Solemani in Chivalry, the Channel 4 #MeToo comedy drama the pair wrote together. He will soon be seen in The Lost King, the film about the discovery of Richard III's remains in a Leicester car park, which he co-wrote with regular writing partner Jeff Pope and which he stars in alongside Sally Hawkins. More recently, he has been filming BBC One drama The Reckoning in which he plays the late DJ and serial sex abuser Jimmy Savile.
Brydon meanwhile, is currently touring with his Would I Lie To You? cohorts Lee Mack and David Mitchell in the show Town to Town and resumes his A Night of Songs and Laughter tour, in which he performs stand-up and sings with a band, on July 3rd.
Gaynor & Ray, a one-off BBC One sitcom that reunites him with Gavin & Stacey co-creator Ruth Jones, about a couple embarking upon their honeymoon in the Scottish Highlands, is also expected to air later this year.