Scottish actor David Tennant goes from BBC's "Casanova" to "Doctor Who," 10th holder of that role after the sudden departure of Christopher Eccleston.

Tennant, 33, played the lothario in the BBC drama written by Russell T. Davies, who is also lead writer on the acclaimed new "Doctor Who."

"Tennant was the only name in the frame to take over. It is a matter of agreeing terms with his agent at this stage," a BBC insider told the Times of London.

The BBC wants Tennant in place to shoot a "regeneration" scene at the climax of the 13th and final episode of the revived science fiction classic. He is then expected to make his first appearance as the Doctor in a Christmas special.

The BBC wants to secure Tennant for the high-profile role before his film career takes off. He is playing the part of Barty Crouch Jr in "Harry Potter and the Goblet of Fire."