The film was originally scheduled to go on floor this September. Shahid couldn't manage dates for the film, which has now been postponed.
Both Sharma and Jaideep Sahni, who has written the story and screenplay, along with Aditya Chopra have taken a creative decision to include lip-sync songs, which were earlier not part of the film.
With other back-to-back projects, Shahid is not able to readjust his dates to accommodate the revised schedule, said a statement from YRF.
Shahid has his hands full with three films - 'Phata Poster Nikla Hero', Bejoy Nambiar's yet untitled film and Prabhu Deva's 'Namak' opposite Sonakshi Sinha.
The director says he understands Shahid's hassles.
"Both Jaideep and I have decided to bring in a couple of lip-sync songs which will need to be recorded before we can go on floor. However, it is sad that Shahid has understandably had to opt out because of this delay, given his packed schedule going forward," said Sharma.
Meanwhile, YRF is said to be in talks with Shahid for another project for next year.