Doctor Who: The Day of the Doctor not only celebrated the BBC franchise's 50th anniversary, but also brought past Doctor actors together in a way that hadn't been done in years, with David Tennant and Matt Smith showing up alongside a new character referred to as War Doctor, played by John Hurt.
But, according to Doctor Who producer Steven Moffat, there was space for Christopher Eccleston, who helped resurrect the show in 2005. According to Doctor Who TV, Moffat says in Doctor Who Magazine #468 that the War Doctor role would have gone to Eccleston if he'd been interested.
"But I was pretty certain Chris wouldn’t do it, although he did agree to a couple of meetings," he says. "So instead we had the challenge and excitement of introducing a BBC audience to a brand new Doctor.” He adds that the Ninth Doctor would have hit the button, but he had concerns. "I was always nervous of that one, because it doesn’t fit with [2005's debut episode] 'Rose' at all."
"[Eccleston] is a brand-new Doctor in 'Rose,' he’s absolutely, definitely new," he continues. "It couldn’t have been is who pushed the button in the Time War, cos that’s a new man, very explicitly, in that episode. I also had trouble, I have to be honest, imagining it being Paul McGann’s Doctor.
“So all of this led me to the idea that if you’re going to sell to the Not-We audience a Doctor who essentially they haven’t seen before, then you have a freer hand than saying it has to be one of the ones you’ve already had. And it was predicated in getting an enormous star to be able to do it. We got John Hurt, so that was cool! Think of the fuss it’s created for us!"
If you missed Doctor Who: The Day of the Doctor when it aired, you can check it out on DVD and Blu-ray now.