Montgomery will operate as the Pirates' opening pitcher in Monday's series opener against the Cardinals, Colin Beazley of the Pittsburgh Post-Gazette reports.
Montgomery will serve as Pittsburgh's opener for the second time this season, having tossed a scoreless first inning in the team's 2-0 win over Washington on April 15. The southpaw has recorded seven straight scoreless appearances, allowing four hits and two walks while striking out 11 over 6.2 innings during that stretch. Wilber Dotel is expected to follow Montgomery on the mound, handling the bulk role against St. Louis on Monday.