The revelation came from an issue of Doctor Who magazine in 2010. Moffat told the magazine (via Digital Spy) that he met Matt Smith at an audition, but not for "Doctor Who."
"He was auditioning — bizarrely enough, if you can picture this — for the role of Dr. Watson in 'Sherlock,'" Moffat recalled. "We'd already cast Benedict Cumberbatch [as Sherlock Holmes] and the very first person we saw for Dr. Watson was Matt, who came in and gave a very good audition. But he didn't have a chance in hell of getting it 'cos he was clearly more of a Sherlock Holmes than a Dr. Watson. There was also something a bit barmy about him — and you don't actually want that for Dr. Watson, you want someone a bit straighter."
Clearly, this audition led Moffat — at least subliminally — to associate Smith with the titular character of his other series at the time. "Oddly enough, I wrote an email where I said, 'I saw this guy today for Dr. Watson and I'd noticed he was on the list for 'Doctor Who' – so the Doctor did flip through my head at that time," he said.
During a filming session with media in attendance, Smith separately revealed that the audition may have given him a leg up later on. "However, Steven saw something in me that made him think I could be right for the role of The Doctor," Smith reportedly told the Daily Mail.
