The BBC wants Tennant in place to shoot a “regeneration” scene at the climax of the 13th and final episode of the revived sciencefiction classic.
He is then expected to make his first appearance as the Doctor in a Christmas special, in which he will team up with Billie Piper, who plays his assistant, Rose.
So if this report is correct, does this mean the BBC want to shoot a different ending to the season than was originally intended?
Or does it mean it was all part of plans for the series, and that they wanted to get the regeneration happening that didn't happen at the beginning of the new series.
There's quite a lot of chatter in the blogosphere to the effect that Christopher Ecclestone's announcement has happened to keep up interest in the show and also to get people excited around the idea of regeneration.
The Daily Mail is reporting that BBC bosses are furious as Ecclestone's departure has ruined all the merchandising they had lined up for Christmas
BBC bosses are furious over Christopher Eccleston's decision to quit as Doctor Who after spending millions on merchandising which carries his image.
They had hoped to cash in on the show's popularity by exploiting the lucrative Christmas market with toys and other merchandise with the actor's distinctive features.
BBC Worldwide licensed Manchester firm Character Options to design more than 20 items. And a 12in action figurine of him is ready to be in the shops by October.
But by Christmas, Eccleston will have already been long departed as the Doctor - his last appearance on television being in June - and will have already been replaced by a new Docousfor the second series, rendering the merchandising obsolete.
There is also the embarrassing possibility that the actor's replacement will already be starring in the planned Christmas special