The Pittsburgh Pirates will go for the sweep of the St. Louis Cardinals, as they battle for the third time in the series finale. Pirates right-handed starting pitcher Mitch Keller makes his 18th start of the season and will face off against Cardinals right-handed starting pitcher Sonny Gray in a meeting of two top pitchers. Keller got just his second win of the season in the first game of this homestand, with a 9-1 victory over the New YorK Mets on June 27.