He told the Radio Times that the former companion, played by Billie Piper, comes back to show "tougher, more independent, and [she] might, at times, seem a little harder".
The departing showrunner sought to reassure fans by adding: "It's still the same Rose Tyler. I didn't bring her back in order to reinvent her!"
After brief appearances in three episodes in the current season, Piper made a full return to the role in previous episode 'Turn Left' and appears in the forthcoming two-part finale.
> Click here for our verdict on Billie Piper's return to Doctor Who