The St. Louis Cardinals made it official on Thursday, purchasing the contract of pitcher Michael Wacha from Triple-A Memphis.
Wacha will start Thursday night's game against Kansas City.
The 21-year-old right-hander was the Cards' first-round selection -- 19th overall -- of the MLB Draft last June.
Wacha was 4-0 with a Pacific Coast League-leading 2.05 ERA over nine starts with the Redbirds. He allowed just 35 hits in 52 innings pitched, holding opponents to a .187 batting average.
To make room for Wacha on both the 25-man active roster and the 40-man Major League roster, the Cardinals optioned right-handed pitcher Michael Blazek to Memphis and transferred left-handed pitcher Jaime Garcia from the 15-day disabled list to the 60-day DL.
Wacha becomes the eighth rookie pitcher to appear on the Cardinals' roster this season and the 10th pitcher age 25 or younger to do so.