The ever-evolving Doctor Who regenerated in Twice Upon a Time, bidding farewell to the Twelfth Doctor (Peter Capaldi) and introducing the Thirteenth Doctor, portrayed by actress Jodie Whittaker, the first female incarnation of the Doctor.
"I think she'll bring herself," Tennant said in response to a fan asking what the actress will bring to the long-running role.
"I don't mean that to sound as flippant as it did. What Jodie has sort of become known for as an actress, she's so brilliantly and heartstoppingly emotional, in something like Broadchurch, where she just broke a nation's heart with this wonderful portrait of this mother and these awful desperate straits," Tennant said.
"And I think people have often gone to Jodie to break our hearts, because she does it so wonderfully. But if you know Jodie, she's so funny and rude and she's got this broad accent, and she's just sort of fizzes with energy and madness. She's quite unpredictable and glorious and funny. And I imagine -- I don't know -- but I imagine she'll bring a bit of that, too, and her natural anarchy will be something that the Doctor will enjoy."
Tennant co-starred in the crime drama, where Whittaker portrayed Beth Latimer. Her time with the series earned her a Best Actress nomination from the Royal Television Society and a nomination for Best Supporting Actress from the Crime Thriller Awards.
"We had a wee chat, yes," he confirmed.
"It is quite a unique job, because it's a show that has so much history to it. And it has a reach that's quite unlike other things. It's a bit of a kind of cultural thing -- Who's going to be the Doctor? -- it's a news story, really. So to find yourself in the middle of that is a bit overwhelming. I think inevitably, you sort of look to people who'd been there before to go, 'What is this like? What is this madness I entered into?' And that's certainly been the case with Matt and Peter, and now with Jodie. I know that Jodie's talked to Peter, and she's talked to Matt. Just for a little support group. You go, 'What is this madness? Tell me about it.'"
"And of course, you know, she 's a little trepidatious, but she's basically really excited," Tennant explained. "She's such a fantastic choice for it. You see it in just those 30 seconds that she did at the end of the last episode. You just go, 'Oh my god, she's all over it. Brilliant. It's great.'"
Whittaker's costume was unveiled in November.
Capaldi, appearing at New York Comic Con in October, offered his own praise for Whittaker during the actor's spotlight panel.
"I've seen what she's done and she's great, and it's in really great hands," Capaldi said.
"I hope people are embracing her and I think it will be wonderful, and I'm glad people were moved by the idea of her."
Series 11 of Doctor Who debuts this fall.