Due to the 41-year-old actor's commitments on 'Batman vs Superman', the big-screen version of Dennis Lehane's novel will now open on October 7, 2016 instead of Christmas Day 2015, according to the Hollywood Reporter.
Affleck is set to write, direct and star in the movie, which takes place in Prohibition-era Boston and centres on the son of a cop who becomes involved in the world of organised crime.
The actor is the only known member of the cast on the project at present.
Meanwhile, 'Batman vs Superman' is due for release in UK cinemas on April 30, 2016 in the UK and May 6, 2016 in the US.