Rock has expressed admiration of McCarthy, who has won Emmy and Golden Globes awards for her performances in Mike & Molly and Bridesmaids.
The actor and comedian recently told the Los Angeles Times about the script, which he says will feature he and McCarthy as a married couple who "indulge in some boisterous dysfunction".
Rock is also gearing up for an upcoming stand-up tour and several other film projects.
He most recently starred in the Sundance favourite 2 Days in New York, in which he played opposite actress Julie Delpy as a disgruntled husband.
McCarthy was forced to pull out of an awards ceremony on Friday (February 3) after contracting laryngitis.
Watch Melissa McCarthy in the trailer for Bridesmaids below: