The showrunner told Entertainment Weekly that it is too early to tell if the CW drama will return for an eighth season.
"We're planning for the worst and hoping for the best," she admitted.
Back in August, The CW president Mark Pedowitz revealed that he is keen to continue Supernatural beyond its current seventh season.
"It's not intended to be the last season," he said. "We'll see where the ratings go. We hope the show keeps going."
The Vampire Diaries star Sara Canning recently filmed a guest role on Supernatural.
The actress will play Lydia, a love interest for Dean (Jensen Ackles), in February 3 episode 'The Slice Girls'.
Supernatural airs on Fridays at 9/8c on The CW.
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Watch a preview for the next Supernatural below: