ST. LOUIS — The St. Louis Cardinals chose Michael Wacha over fellow rookie Shelby Miller to start a potential Game 4 of the NL division series.

Miller led major league rookies with 15 wins but Wacha (4-1, 2.78) is fresher and gets the nod Sunday against Pittsburgh’s Charlie Morton (7-4, 3.26). Manager Mike Matheny said it was hard to ignore Wacha’s near no-hitter against the Nationals last week. Wacha fell one out short of the no-no in his final regular-season start.

Miller warmed up in the Pirates’ two-run third during Game 2 on Friday. Both rookies had been available in the opener.