Christopher’s absence in the 2013 episode 'The Day Of The Doctor' didn’t go unnoticed with viewers at the time, and Steven has now revealed that he did his best to convince the actor to appear in the show.
During a chat with Radio Times, Steven explains that he rewrote the episode’s script at Christopher’s request, but he still ended up declining the offer.
"But it’s reasonable to say he really cares about ‘Doctor Who’."
Steven then had to rewrite the episode, which was simulcast in November 2013, being screened in various cinemas, as well as on TV in over 90 countries.
Christopher quit the hit show after just one series back in 2005, and he later admitted that he didn’t exactly see eye-to-eye with bosses.
"I don't think it's important that I left - I think it's important that I did it in the first place.
"Myself and three individuals at the very top of the pyramid clashed so off I went,” he said in July. “But they're not here to say their side of it so I'm not going into detail."
Read Steven’s full interview in the latest issue of Radio Times.