As "Doctor Who" season 8 continues filming, former Doctor Matt Smith has expressed regret in leaving the reign to Peter Capaldi.

“I rang Steven Moffat up the other day and found out everything about the new series. It sounds really good! I was really jealous actually," said Matt Smith at the Calagary Expo panel.

“You never really think you’re going to leave and then it comes and you’re like ‘Oh no. What am I doing? Why have I left?’ There’s a lot of that.”

Unfortunately, it seems unlikely Matt Smith will return to "Doctor Who" unless there is another anniversary celebration. Plus, there is a lot of positive buzz with Peter Capaldi.

According to Radio Times, five episodes have been filmed for "Doctor Who" season 8 featuring Peter Capaldi.

Reportedly, Peter Capaldi looks on track to "make one of the best Doctors ever."

“There is a real buzz about this Doctor, and of course the monsters are great," says the article according to Doctor Who TV.

In addition, the chemistry between Peter Capaldi and Jenna Coleman is "sizzling," albeit different from her dynamic with Matt Smith.

Peter Capaldi is “more distanced from his assistant, more of a mystery. Less a mate, and someone she looks up to. She has to try and gauge him – but dramatically it’s very satisfying and onscreen they work very well together.”