Pitching in the piggyback system the Astros employ in most levels in the Minor Leagues, McCullers has thrown 28 2/3 innings in four starts and three relief appearances this season. He has a 2.51 ERA and has struck out 33 batters and walked 12.
Right-hander Kyle Smith, the Astros' No. 19 prospect, relieved McCullers. He allowed three runs (one earned) on six hits and struck out seven batters in 3 2/3 innings.
-- Teddy Cahill
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.