The series, which stars Will & Grace actress Debra Messing, Anjelica Huston, former American Idol contestant Katharine McPhee and Jack Davenport, will revolve around a group who team together to stage a Broadway show based on the life on Marilyn Monroe.
Speaking as part of the 2011 upfronts, Greenblatt confirmed that he chose to hold Smash back due to the show's "compatibility" with returning reality series The Voice.
"Smash is a priority, which is why it's leading out of The Voice," he explained.
Greenblatt also revealed that he was pleased with the decision to launch new comedy series Up All Night and Free Agents on Wednesdays, while returning sitcoms Community, Parks and Recreation and The Office remain on Thursdays.
"I would love to expand the [number] of comedies on a night other than Thursday," he said.
> NBC unveils 2011-12 lineup
> Night By Night: NBC's 2011-12 lineup
> Scorecard: What's in and out at NBC
Watch a clip from NBC's new series Smash below: