The showrunner first introduced Captain Jack in the series one two-parter 'The Empty Child'/'The Doctor Dances' for a stint with the Ninth Doctor (Christopher Eccleston) and Rose (Billie Piper). The rogue Time Agent proved to be such a hit that Barrowman was eventually granted his own spinoff series, Torchwood.
In an interview with The Gothamist, Moffat responded to a questioner's suggestion that he has resisted using any characters that originated from former executive producer Russell T Davies's reign.
"There's no rule against that," the writer asserted. "People talk as if somewhere there's been some schism."
He added: "I mean, Jack, who I wrote in the show, I'd love to have him back. I was thinking he should really be here recently but he's busy [filming Torchwood: Miracle Day].
"And I mean there are references to Davies's characters - we just had a reference to Rose, in fact. In my head there is a continuing story. There's no idea that we're abandoning anything. There is an element that The Doctor moves on from people in a rather scary but inevitable way. He won't be nearby forever."
The sixth run of Doctor Who began last weekend with 'The Impossible Astronaut', which saw the Tardis crew being forced to keep a grave secret from The Doctor and the debut of a dangerous new foe.
Doctor Who returns with new episode 'Day of the Moon' this Saturday on BBC One in the UK and BBC America in the US, while Torchwood: Miracle Day premieres in July on BBC One in the UK and Starz in the US.
> Read ten teasers about 'Day of the Moon'!
Watch the teaser for Captain Jack's return in Torchwood: Miracle Day below: