The contest never got underway. No makeup date was immediately announced.
The Brewers return home to play host to the St. Louis Cardinals on Thursday in the opener of a four-game series. The Pirates stay home for the start of a four-game set with the Arizona Diamondbacks on Thursday.
Milwaukee is scheduled to visit Pittsburgh again July 12-15 and Sept. 21-23.
The Pirates won the series opener 1-0 at PNC Park on Monday, and the Brewers won 3-2 on Tuesday.
--Field Level Media