Jeff Locke will make his major league debut Saturday in a start against the Marlins. He's taking the spot of Charlie Morton, who the Pirates want to rest. Locke, who came over from the Braves in 2009 as part of the Nate McLouth deal, posted a 3.70 ERA and 139/55 K/BB ratio over 153 1/3 innings between Double- and Triple-A this season. He will likely compete for a rotation spot with the Bucs next spring.