Nina Tassler told reporters that she had always been reluctant to drop the series, TV Guide reports.
"I did not want to let [Unforgettable] go," Tassler explained at the Television Critics Association press tour.
"I can't predict what our expectations for it will be in the summer [but] I think it will fare well."
Unforgettable will return to US screens in 2013. Series star Montgomery has already signed up for the new episodes, as have her co-stars Dylan Walsh (Lt. Al Burns) and Jane Curtin (Dr. Joanne Webster).
However, Michael Gaston (Det. Mike Costello), Kevin Rankin (Det. Roe Saunders) and Daya Vaidya (Det. Nina Inara) will not return as series regulars, it has been confirmed.
The show's first season aired on Sky Living in the UK.