Thanks to Digital Spy for the text and interview below:
He told Zap2it: “I’ve always said that if I’m asked to go back to Doctor Who, I’ll go at the drop of a hat. That’s where Captain Jack got his beginnings.”
He added that Jack’s possible return had “already been discussed” by Doctor Who showrunner Steven Moffat and Torchwood creator Russell T. Davies.
“It’s in the cards, but who knows whether it will happen?” he said.
Barrowman also praised current Doctor Who star Matt Smith, but admitted that he still feels “attached” to his former co-star David Tennant.
“I like Matt Smith [and] he brings his own quirkiness to it,” said the star. “When a new Doctor starts, everybody goes along for the journey because they love the show. But then you attach yourself to that Doctor.”
Barrowman continued: “There’s a whole new generation who are now attached to Matt, and rightly so…. but David Tennant is my Doctor.”