This means that the first chance American fans will have to catch stars Peter Capaldi and Jenna Coleman before the show's premiere on August 23rd will be as part of the recently announced Doctor Who: The World Tour (read more here), which reaches New York on August 14th.
A representative for BBC America made this statement:
"Doctor Who's cast and creators will not be in attendance at Comic-Con International: San Diego 2014. They are currently in production until August on the upcoming season - 12 all new back-to-back episodes.
"Given the unprecedented success of the global event around the 50th Anniversary, BBC America and BBC Worldwide will launch the first-ever Doctor Who world tour in August to celebrate the new chapter of the series starring Peter Capaldi."The Doctor Who panel has been a firm fixture at SDCC in recent years, and from 2011 onwards has been upgraded to Hall H to feature alongside other highly acclaimed shows such as Supernatural and Breaking Bad. The last time Doctor Who skipped the popular fan convention was in 2010 - incidentally the same year that Capaldi's predecessor Matt Smith made his debut in the show.
Despite the lack of a panel, Doctor Who will still have a presence at SDCC this year in the form of a merchandise booth from BBC America along with a giant video wall displaying fan art and fan videos, which were submitted by fans via the official Doctor Who Tumblr earlier this month.
San Diego Comic Con 2014 will take place at the San Diego Convention Centre from July 24th to July 27th.
[Source: Doctor Who TV]