Top prospect Wacha continues to roll at Triple-A

Top prospect Wacha continues to roll at Triple-A

ST. LOUIS -- Highly touted pitching prospect Michael Wacha lowered his season ERA to 1.89 ERA with the most dominant start of his professional career on Thursday.

Wacha, the Cardinals' top pick in the 2012 First-Year Player Draft, retired the first 13 Tacoma batters he faced en route to finishing seven innings for the third time this season. Rich Poythress' home run cost Wacha the shutout, but it was one of only two hits the right-hander allowed. Wacha walked one and struck out eight in the outing.

"It sounds like he's doing everything he needs to do right now," manager Mike Matheny said of Wacha, the organization's fourth-best prospect according to

Wacha remains undefeated in Triple-A, though the Memphis bullpen cost him a fifth win on Thursday. Since being knocked around in his first Triple-A start, Wacha has held opponents to eight earned runs and a .159 batting average over 43 2/3 innings.

Jenifer Langosch is a reporter for Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.