Watertown - A state Supreme Court judge on Wednesday reserved decision regarding an injunction to block the city from a new policy that prohibits firefighters from being called into work when their colleagues call in sick. Last month, the City Council decided in executive session to establish a new policy that will not allow firefighters to be brought into work when others call in sick, a move that City Manager Sharon A. Addison admitted violates the union contract. The union promptly filed a grievance. Following oral arguments by attorneys, Judge James P. McClusky said he would make his written decision known within a week. The city and Watertown Professional Fire Fighters Association Local 191 are in the midst of a bitter three-year contract dispute. The new practice of “not backfilling” sick firefighters began on Nov. 12.